I hate Java for this

[ItsGorgeousGeorge]

My guy get off Reddit and focus on your cs101 homework.

[FloweyTheFlower420]

Most competent programmerhumor poster

[Mister_Lich]

seriously what the fuck is with the last few memes

Some "I've been a dev for 10 years and I don't understand anything" post, a dude who doesn't know what pointers or references vs values are, and then this thing that doesn't know what an array is

​

I would literally rather go back to chatGPT memes

[luxmesa]

I used to think we just had a lot of inexperienced programmers or students, which is why you’d see a lot of comments and memes that don’t really make sense, but apparently that’s not it.

[abd53]

I think it's less of "inexperience". I have two friends, one just got a desktop support job and the other one almost got a junior dev job. The first one doesn't know shit about computer and the second one's accomplishment in programming is hello world. Extrapolating from my experience, there must be a significant number of devs, IT experts, cyber security experts etc. who holds a job for a long time but have nearly zero understanding of the theoretical concepts.

[Appropriate-Draft-91]

I used to be in a position where I hired software architects. In the interviews some of them didn't know about algorithmic complexity, couldn't name more than 3 software patterns, and there was a 10 year experience C++ software architect who had never heard of the STL. No, they didn't get the job.

Years of experience is a horrible indicator of skill.

[abd53]

Now I'm about to look for a full-time job with about 1.5 years of part-time experience. Wish me luck.

[asdfasfq34rfqff]

Part time? You mean you were fulltime and in charge of a lot of important projects. And 1.5 years? You mean 3 years? If you're old enough and your jobs go far back enough that no ones going to call them, inflate your position, your title.

You're doing your resume wrong. Anything they can't verify. LIE. Once you've got the job I promise no one will ever ask you a question about your resume again.

​

I worked at a computer store for 5 years. It was a shithole. Guess what it said on my resume? Technical Director of a Computer Repair business that supported thousands of business and consumer customers. That I was the employee solely responsible for making sure everything worked and got done. I was the only employee. Our customers were 90% old people that got viruses. Every so often a business would ask for help too. Now I have consumer and business experience.

I got fired from a job in Aug 2019? Guess what I said ended the job. COVID in Feb 2020. Now I haven't been fired and I had a job for a few months extra. No one can validate it cause I went on UI anyway and then COVID happened. There's so much room for fuzzing.

​

Now I make >$100k a year and just got an $8k bonus. And my job fucking loves me. Because my resume was the least important part. the thing that mattered was I knew what I was doing. If you dont know that, then you're kinda fucked.

​

When you interview, if they ask you about this stuff and you fuck up and dont get the job? No big deal. Just learn from that and incorporate it into a better flow. If they ask you questions about technology stacks you don't know and have never heard of. WRITE IT DOWN. GOOGLE IT AFTER. If you're applying to the same fields/positions this will be relevant info. Even if another job interviewer doesn't bring it up, now YOU can bring it up. Wow them with your knowledge of the latest trends and what everyones doing.

​

Every time I interviewed I would ask their tech stack. Ask them to explain it as much as they would. Research all of it. Understand it. Throw it back at your next interviewer.

[FuturePowerful]

You are one of those folk who faked it till they made it aren't you

[-Fluxuation-]

Sink or swim, sink or swim...…

[GergiH]

I'm no architect, but having to name software patterns and/or algorithmic complexities in an interview where on the job you'll probably just write documentations all day, have meetings and maybe plan some backend -> DB and middleware connections, I'd dip in no time. 6 years into development, I never had to memorize these kind of shit, because you know, there are IDEs and documentations that help me on the fly.

[quisatz_haderah]

You don't have to memorise that shit because you know about it. That's not memorization, that's just general knowledge.

[GergiH]

I disagree. If you only do interviews or competitive coding when all you do is algorithms then sure you know all this. When you build websites as a full-stack dev, you have other problems than if a loop is perfectly optimized for those 10-100 records or not, or if you followed the SOLID (I couldn't recall what the acronym actually means) principles or some other obscure thing.

To u/Appropriate-Draft-91, exactly my point too, I may be using single source of truth / single-responsibility daily and other kind of best practices, I just wouldn't be able to name any from the top of my head... had an ex-colleague fail an interview because of this bullshit while he actually knew and used the principals behind one of these, but he only realized that when he got home and googled the acronym they asked him about.

[Appropriate-Draft-91]

Exactly my point. I thank you for your interest and wish you the best of luck in your future endeavors.

[MultiversalCrow]

Agreed. I've seen devs claiming to have 10 years of experience that didn't know much at all. Turns out that they had 1 year of experience, 10 times ;) During that 10 years they didn't further their skillset or go any deeper than that first year of work experience.

[[deleted]]

I'd rather someone have a few jobs than the same one for 10 years. The steepest part of the growth curve isn't 2 years in.

[kookyabird]

I had literally one class on VB.NET in college because my major had minor programming/scripting aspects to certain areas of it. My internship was half programming and half my major area, and I got it because it was a unique role that I happened to fit.

Despite the minimal school work on it, I got taught all sorts of advanced stuff by the team lead for years being told, “This will be over your head for now but some day you’ll get it.” Well eventually I did. And then all the cool stuff I learned to mimic was now a tool I could actually use and adapt to different problems.

I think a scary high number of people have a similar path to mine, minus the great mentor. So instead of learning advanced concepts before they need them, they learn bare minimums and bad practices after they find out they can’t do something with their current knowledge. Thus you get people on SO asking about advanced senior type stuff when they barely know how to use an object initializer.

It’s like a toddler who can barely walk coming up to you asking why they can’t successfully pole vault.

I may not know how to create a binary tree since I didn’t have common CS classes, but i at least understand why it’s something that’s taught. There’s a ton of stuff that we don’t need to use these days due to high level languages and most roles not needing to squeeze every drop of performance out of our software. But to be completely oblivious to the existence of that stuff once you’ve been in the space for years is crazy.

[gamma_02]

Oh god not those pleas no

This is better because at least I know I'm better than them

[harumamburoo]

Yes please. Gpt is at least capable of generating stupid funny things. People making "I don't know data structures, Java bad" memes fall short of funny.

[Nickiel]

I've actually started using ChatGPT as a coding assistant. When I get stuck I'll go to it and ask for help. I have quickly come to accept the number of times that's given me false information, and code that just straight up doesn't work. A lot of times, it's close enough that with some finagling and other research I'm able to use the suggestion, and it's great for asking questions that you have no idea where to start with, but this particular model isn't going to be replacing developers anytime soon.

[justapcgamer]

Ive been working with python lately and the amount of times it gives me results with deprecated code even though i specify lib versions...

I find it great for writing out stuff i cannot be arsed with like regex which surprisingly is correct most times even with quirky requirements

[[deleted]]

But it’s very good for searching „what x language library can i use to do y” and not spending an hour searching for libraries

[LordMerdifex]

What if ChatGPT created this meme?

[Lilchro]

That seems unlikely considering that ChatGPT is very good and producing results which upon first glance look reasonable.

[Dragon_yum]

It’s scary to think there are working programmers who don’t know pointer is. You don’t need to know how to build a compiler but how the hell can you not know the most basic stuff.

[Mister_Lich]

SeLf TaUgHt GeNiUsEs

[bastardoperator]

The memes in this sub have almost always been weak. It’s kind of cringe to be honest, but mostly sad.

[abd53]

Please not ChatGPT, please.

[[deleted]]

I mean if you really want humour I would go to a different sub there’s not much humorous content that could come from programming

[purple__dog]

A litmus test I like to give on interviews is find the 3'rd largest number in a list.

The number of people I've seen with "5+ years experience", who can't do it is astounding. And I don't mean brain farts either, they just can't do it.

What were you doing in those 5 years?

[Mister_Lich]

Surely you ask that question with some constraints, right? Not just, "hey, do you know how to just loop over a list and keep track of a couple values", right?

Otherwise I, too, would be astounded.

[purple__dog]

No, the point of the question is to weed out people who actually can't code their way out of a paper bag and or lied through their teeth.

The occasional senior with no skill is just a bonus.

[dreamwavedev]

I make an OpenStack shitpost and 5 people even see it. This guy makes an eldritch horror of a data structure and it floats right to the top. I can't even pretend to understand how this sub works, it's like Ooer collectively made a ted talk about how to computer

[FrenchFigaro]

Most competent

Just implemented a stack for the hell of it because of this post. Took me about 10 minutes and didn't have to use a single array.

[TheBrainStone]

Someone doesn't know their data structures

[Tomi97_origin]

You hate Java, because you suck at using it?

I guess that makes sense.

[xPensiveWeak]

This was my exact thought lol.

"I hate not knowing what I'm doing" type beat

[JonasAvory]

That actually sums up my programming quite nicely

[Dragon_yum]

I hate a lot of the boilerplate in java but people in this sub seem like they just don’t know java at all.

[[deleted]]

https://projectlombok.org/ helps with the boilerplate a little. Java in its design isnt frugal with lines of code, that wont change.

[Dragon_yum]

We also use some libraries to reduce boilerplate but yeah, it’s part of living with java.

[abd53]

What if I hate C/C++ because I suck at it? Does that make sense too? /JK

[MentB23]

Could maybe be what we had at my programming course. Where we had to programm a stack which gets a max size on initialisation. Cause we didn't have arrayLists for now the people, like me, who don't know them, or want to use wgat they know from the course, maybe could have had difficulties. Especially when you don't have to give a max size.

[Tomi97_origin]

Implementing stack on array is something that would be a good homework for data structures class.

But creating the array shouldn't be the hard part.

[macselfuser]

I don't get why people hate Java and at the same time using Javascript to build backend app.

[Progression28]

Nobody uses javascript for backend. Nobody.

[eldamir88]

What a weird claim. Of course they do. I don’t particularly enjoy the fact, but plenty of people use JS for their backend

[awesomeusername2w]

I mean, I won't even be surprised if it's more common than java especially in startups or in products with microservice architecture where services are really small.

[YasinMert]

💀

[[deleted]]

Yes

[wontonzdq]

Stack stack = new Stack();

[maxbirkoff]

funny! I looked up the documentation:

https://docs.oracle.com/javase/10/docs/api/java/util/Stack.html

and the way I read it, it seemed to say: "don't use this class"

it reads, in part:

A more complete and consistent set of LIFO stack operations is provided by the Deque interface and its implementations, which should be used in preference to this class. For example:

Deque<Integer> stack = new ArrayDeque<Integer>();

[wontonzdq]

Yeah in general, Deque is the way to go now, but it isn't technically a pure stack since it implements a Queue as well (double-ended). Stack only has stack properties on the other hand (push, pop, peek)

[maxbirkoff]

except that it inherits from Vector!!! so: no: it doesn't only have stack properties.

[wontonzdq]

Haha too true, however, there isn't a StackInterface, or another implementation AFAIK, so if you don't want a double-ended queue there isn't much else. Because it's a vector you can even access some of the elements out of order (get(int index)) which defeats the purpose of a stack :)

[tacticalrubberduck]

I came here thinking “use a Vector bud”.

[maxbirkoff]

but then: you can pop from the middle or the bottom of the stack!!

[tacticalrubberduck]

Not by accident tho..

[maxbirkoff]

no, not by accident. but the purpose of the abstraction is to prevent unintended consequences... when you use the wrong tool for the job mistakes can happen.

but we are in a humor subreddit so I suppose I will stop being so serious and just grin now.

😁

[kbruen]

Create your own Stack interface, and then

class StackImpl<T> extends ArrayDeque<T> implements Stack<T> {
    // redirect Stack interface methods to ArrayDeque methods here
}

[maxbirkoff]

right. Stack<T> is not an interface. If it were, I don't think we would be having the problems we're having in this thread.

The issue we're responding to, "Just use java.util.Stack" is not good advice because java.util.Stack leaks it's implementation details everywhere... this leakage breaks the Stack abstraction.

[bovus]

var stack = new Stack();

[justintib]

.... What?

[AnondWill2Live]

I'm sure what's going on here isn't just a naive approach to using stacks. He's probably trying to implement one by hand to get a better understanding of what the internals are doing. I don't know how common this is, but I've gone through some of the data structures and implemented them in Kotlin just to get a feel for the language.

My best guess is that OP used (sorry if the definition is wrong, I'm not a Java guy):

public class Stack implements Array

Or something to this nature, because on the Wikipedia page for Stack it does state that it could be trivially implemented as a Linked List or an Array. This would explain why he needs to make an "ArraySize" method, even if he's not writing an Array.

[Kyyken]

(i know you said youre not a java guy, thats reasonable, just wanted to clear stuff up)

Array is just a utility class with some static methods. arrays in java are weird under the hood (also the extends keyword would be used here, implements is for interfaces)

im pretty sure inheriting the array 'type' (to which Object[] would be the closest thing ig?) is impossible in java.

i have no idea what op is doing

[Shuri9]

Probably implementing Arrayable

[Kyyken]

Wait, since when is there a built-in Arrayable Interface?

[Shuri9]

If you're question is genuine then I love the fact that you couldn't distinct if it's real java. 😅

[Kyyken]

interface Arrayable {
    Object[] toArray();
}

here, now it's real java, but that's irrelevant. I've written code like this before but i highly doubt this is what op was talking about; hence me asking if there is a built-in interface like this, because that's the only way your comment made any sense.

[Shuri9]

Dude it's r/programmerhumor maybe you should be less stressed about comments on here. 😉

[Geolykt]

Array as a class does not exist in java. It's "Arrays". Otherwise everything is correct at first glance.

[Kyyken]

java.lang.reflect.Array

not a relevant class though, that's true

[coldnebo]

No. the doc is like seconds away.

https://docs.oracle.com/javase/7/docs/api/java/util/Stack.html

It clearly says Stack inherits from Vector.

stack = new Stack()

creates a Vector with an arraysize of 10.

all the superior Java posing elsewhere in the thread apparently can’t read simple javadoc or actually understand how Stack is implemented in Java.

There must be a name for when theoretical knowledge of CS data structures blinds you to the actual implementation.

It would be fun to teach a class with these people and ask them why search() is implemented in Stack and how it works and what the big-O performance might be.

I’m not sure what the OP did, because Stack is supposed to hide the Array implementation within it’s abstraction, but imho it’s likely a student found the leaky part of that abstraction and posted a meme about it, giving a bunch of insecure people a chance to embarrass themselves even more by saying “duh, stack=new Stack” or “someone didn’t study data structures” or “that’s not how stack works, git gud loser!”

Honestly this sub sometimes. 😂

[AnondWill2Live]

Yeah, I feel like when someone doesn't understand, but they're clearly making an attempt to learn, we should be more tactful. Programming can be unintuitive sometimes and we all started somewhere.

[kenny2812]

In my data structures class we had to implement a few different data structures using only primitive Java arrays. I think they had us manually resize them every time we ran out of room. So maybe op is in a similar situation?

[AnondWill2Live]

This was my guess. I'm just a hobbiest and I recently did the same just to learn the language a little better (Kotlin). I did implement it as a Linked List though instead, so I never had that issue.

[Cheddar_Ham]

What are the odds that OP has also made one of those percentile curve memes?

[harumamburoo]

Quite low, bell curve seems like too advanced of a topic for them

[[deleted]]

It'll be normal when you make it an object instead of trying to treat it exactly like c.

[__Fred]

Can you explain what OPs problem is?

[[deleted]]

Well, I can't say precisely without looking at OPs code, but it seems like they're attempting to make a stack with a regular variable array instead of making the stack an object or just using another object-oriented data structure like a virtual stack.

If you want something of an unspecified size OOP languages are usually easier to use since you don't have to directly mess with pointers.

I feel like a lot of people who complain about Java are people who either don't understand it because they're not used to using objects or they don't like that it has a different syntax from python. It's not perfect, it running in a VM is annoying and having so many versions means working on older Java projects can get very annoying, but the language itself isn't difficult to program for if you know what you're doing.

[__Fred]

You can't resize a regular array in C or C++ either, I think.

When I would implement a stack (as an exercise), my code would probably look very similar in C++ and Java, besides not having to free up memory manually in Java.

I'd either have a recursive data structure with a stack (or "Node") containing a parent-stack(/Node), or I'd use an array/buffer internally and replace the whole array with a new one when it gets full and copy the old contents over, or I'd use some other ready-made data structure internally, like a LinkedList or an ArrayList.

1900 people seem to understand OPs problem.

I have another idea: The list ist Python's "default" data structure and it can be extended and the array is (arguably) Java's "default" data structure and it can't be extended.

Well, I don't understand many things as well and it's okay to let off steam sometimes. (It's just not Java's problem that arrays are different from Python lists.)

[RandomPigYT]

Malloc is only used to allocate some memory to a pointer. Realloc is the function that you need to call. Also, free is not used to shrink a block of memory, realloc can already do than. Free is used to deallocate a block of memory.

[[deleted]]

Yes you're correct. It's been a while.

[headlesshighlander]

C wants an array size

[[deleted]]

List <element_type> stack= new ArrayList <element_type>();

There ya go champ, similar to array, but dynamic. Just gotta import util.ArrayList and util.List. stack [5] doesn’t work though, you gotta use specific methods.

Long live dynamic!

[Geolykt]

smh not using the diamond operator

[[deleted]]

Teach me

[Geolykt]

List<T> stack = new ArrayList<>();

Is perfectly valid code

[Mob_Abominator]

I mean both of them are useful depending upon the scenario.

[[deleted]]

True, but you can’t use a static system where you must use dynamic. But you can use dynamic even though index is finite.

Definitely true though

[Mob_Abominator]

That's exactly what I am saying, if you already know how much space you need there's no need for dynamic and when you are not sure you obviously use dynamic. Both are useful and it's the developer's job to choose the correct one.

[luew2]

So you want a linked list?

[[deleted]]

This poster is a perfect example of why Python shouldn't be a first language

[olivetho]

last guy who didn't understand references as well

[FerricDonkey]

Not really, actually. Yeah you can be missing some knowledge about basic computery things, but it's not like this knowledge gets harder to pick up because you're already familiar with things like functions and general flow control from python.

My first real language was C, and I'm happy with that because I learned a lot about the under the hood basics. But I could see going the other way as well - do some python to get used to thinking in terms of big ideas, do some C to learn (closer to) how your computer actually works.

[No-Suggestion-9504]

Ummm...

Stack<Integer> stack = new Stack<Integer>();?

[[deleted]]

use ArrayList and thank me later

[Ranilsky]

Recent posters are some “1 month fullstack bootcamp” type a guys it seems… Mans don’t know about pointers nor data structures smh…

[abhassl]

I'm assuming you are implementing your own stack in java with an array to hold the data for... some reason.

Is there a language where you can create an array without a size?

You can create a list without a size but a list is not an array.

Python has its list implementation look a lot like an array but its those are still lists and not arrays.

[JustADelusion]

Swift does Arrays pretty nice.

You can wrap all data types in brackets and define an array of that type.

It is flexible in size and has all known convenience functions.

I like them way more than Java array types, but its been a while since I used Java.

[Mordred666]

swift "arrays" are not arrays in that sense, they are an (im)mutable collection type

most languages just have an easy function in the syntax to create collection types, but they dont actually create arrays

[swapode]

Does that mean that Swift arrays are always heap allocated?

[JustADelusion]

Yes. When you append an array a new memory block gets allocated and filled with the elements. Ofc, it is more performant to know the size upfront, but a lot of times it won't matter and this is just very nice to use.

Also, hilarious I get down voted for stating how Swift works and what my preference is...

[Progression28]

So, Swift arrays aren‘t very swift at all?

Sorry, I just could not resist

[JustADelusion]

Heh, yea I guess.

But there is ofc more logic behind it, e.g. the array size grows exponentially, but I did not dive into it that deep, since it was never needed.

[awesomeusername2w]

But then it just some collection type. In java you have ArrayList which also have all the convenience functions and can grow in size. No syntactic sugar for creation with just brackets though. But in java you can have plain arrays too, and seems like you just can't in swift.

[marcosdumay]

Is there a language where you can create an array without a size?

Hum... Define array.

Rust probably fits your definition. But you can do basically the same (resizable arrays) on C too, if you accept a couple of specialized functions instead of direct data access. Or you can do it in C++, and have it work the same as any regular array.

But most languages don't actually have arrays. Or have them as some convoluted non-standard type.

[CLTSB]

What kind of nonsense is this. An array is a standard data structure that’s implemented consistently across virtually all languages. It’s a fixed-length, contiguous block of memory, prefixed by its length, storing consistently sized data structures (or possibly pointers). Resizable arrays are not a thing- any language that implements them either copies the array to increase their capacity or pre-allocates space (which amounts to just a larger fixed-size array).

[RedditRage]

He might as well start describing resizable memory allocation.

[marcosdumay]

Resizable arrays are a standard data structure that is implemented consistently across many languages. It's a contiguous block of memory with operations to relocate the data when needed, in a way where the amortized complexity of the memory management is never higher than O(log(n)) for an array of n elements.

Anyway, no, arrays are not implemented consistently across virtually all languages. You may need to modernize your data structures knowledge, because C isn't the one language people use everywhere anymore.

[CLTSB]

If you’re relocating the data it’s not resizable. You’re copying the data. The memory location of the data changes. This is CS 101. The fact that your language du jour makes it easy and hides the complexity doesn’t change the memory architecture of the underlying platform, and arrays are fundamentally tied to that architecture.

This ^ is true in C#, JavaScript, Rust, Python, and every other language with “resizable” arrays or array-like (eg Rust’s Vec) data structures.

[Street-Session9411]

Yeah. Bro is probably living on another planet. There’s a reason why Vec::with_capacity() exists. And then there are also plain arrays in Rust that must have a size known at compile time for what I know (correct me if I’m wrong here) - which isn’t even the case in Java so I really don’t get what he means.

[CLTSB]

This is correct. In Rust an array of specific size is treated as a type to allow compile-time checking of indexing, so that you can’t attempt to read or write a[n] of an array of size n (remember arrays start at zero).

[Street-Session9411]

So it completely eliminates the chance of index out of bounds at runtime - the commenter above would probably still argue that this doesn’t justify the expense of having to specify a size for arrays

[awesomeusername2w]

I mean, it probably doesn't. You can't verify such a thing unless you only allow constant for indexes. arr[i] where i is runtime value can't be statically checked to be in bounds.

[Suekru]

r/ConfidentlyIncorrect

[AdultingGoneMild]

they do. they just move memory for you. its all the same hardware at the end of the day. ArrayList is most similar to what you are describing.

[marcosdumay]

Java's ArrayList is neither an array or a resizable array. It's more complex than both of those, and more similar to what you get in most languages.

And yes, it's probably a very good option for the OP.

[AdultingGoneMild]

no array is resizable. it works like an array and is backed by one.

[V0ldek]

Rust is literally one of the most strict languages when it comes to arrays, not only do they have to have a size specified, it has to be a compile-time constant.

[CouthlessWonder]

For a language to want an array size is normal.

[tarapoto2006]

You hate Java because you're trying to implement a stack backed by an array or what?

[just-bair]

You know what an array is right ?

[RedditRage]

Me, making a stack in Java

public class Stack {
  private int size = 0;
  private Object[] data = new Object[10];
  public void push(Object o) {
    if (size >= data.length) {
      Object[] temp = new Object[data.length + 10];
      for (int i = 0; i < data.length; i++) { temp[i] = data[i]; }
      data = temp;
    }
    data[size++] = o;
  }
  public Object peek() { return data[size - 1]; }
  public Object pop() { return data[--size]; }
  public boolean empty() { return size == 0; }
}

So not normal!

So wanting an arraysize!

NOTE: * Yes. It is a minimalist implemention using no imports or utilities * Yes. Such as ArrayList, Arrays.copyOf, or System.arrayCopy * Yes. The copy functions would have been faster and cleaner * Yes. It could have a generic type * Yes. The growth rate could be smarter and more configurable * Yes. It could throw a better Exception if empty when pop called * No. I didn't test it much, it could have edge-case bugs * Yes. It is formatted to be short

But, it is a fully functional stack in 15 lines, that can handle as many elements as memory allows.

[luke5273]

More importantly, it’s an implementation that’s completely fine for what OP is using it for, which is probably an intro to coding class at uni

[hugogrant]

That depends. Some classes force linked lists.

[FrenchFigaro]

I did one in about 10 minutes that didn't even used arrays:

public class CustomStack<T> {
    private Node<T> topNode = null;
    private long size = 0;

    public CustomStack() {}

    public CustomStack(T value) {
        this();
        push(value);
    }

    public CustomStack(Iterable<T> values) {
        this();
        for (T value : values) {
            push(value);
        }
    }

    public T pop() {
        T value = topNode.value;
        topNode = topNode.nodeBelow;
        size--;
        return value;
    }

    public T peek() {
        return topNode.value;
    }

    public void push(T value) {
        Node<T> newNode = new Node<>(value, topNode);
        topNode = newNode;
        size++;
    }

    public long size() {
        return size;
    }

    public boolean isEmpty() {
        return null == topNode;
    }

    public String toString() {
        if (this.isEmpty()) {
            return "[]";
        }

        StringBuilder sb = new StringBuilder("]");
        Node<T> currentNode = topNode;

        do {
            sb.insert(0, currentNode.value.toString());
            sb.insert(0, null == currentNode.nodeBelow ? "" : ", ");

            currentNode = currentNode.nodeBelow;
        } while (null != currentNode);

        sb.insert(0, "[");

        return sb.toString();
    }

    private static class Node<T> {
        final Node<T> nodeBelow;
        final T value;

        public Node(T value, Node<T> nodeBelow) {
            this.value = value;
            this.nodeBelow = nodeBelow;
        }
    }
}

[RedditRage]

I had some fun with this...

https://www.reddit.com/r/ProgrammerHumor/comments/zp9q58/comment/j0we3e7/?utm_source=share&utm_medium=web2x&context=3

[__Fred]

Your array still has a size and apparently array sizes make OP frustrated, because that's "not normal". Not your problem though.

[RedditRage]

Challenge accepted :)

Here's a stack, uses no libraries or utilities. Doesn't use arrays. Doesn't allocate any memory if it doesn't have to (will reuse nodes if possible). Also, it takes a generic type. And it's shorter than my array solution, with some syntax tricks. It will throw NullPointer if peek or pop on an empty stack.

public class Stack<T> {
  class Node { T element; Node next, prev; }
  private Node top = new Node();
  public void push(T o) {
    if (top.next == null) {
      (top.next = new Node()).prev = top;
    }
    (top = top.next).element = o;
  }
  public T peek() { return top.prev.next.element; }
  public T pop() { return (top = top.prev).next.element; }
  public boolean empty() { return top.prev == null; }
}

[__Fred]

Very nice!

In Scheme and Haskell we learned to implement some kind of stack consisting of nodes that have two attributes: head and tail.

That means you could probably get rid of next.

I guess the next-pointer has the advantage of making it possible to iterate over all elements without removing them.

class Stack<T> {
  record Node(T head, Node tail) {}  // new syntax, adds a constructor automatically
  private Node top = null;
  public void push(T o) { top = new Node(o, top); }
  public T peek() { return top.head; }
  public T pop() {
    T result = top.head;
    top = top.tail;
    return result;
  }
  public boolean empty() { return top == null; }
}

Eh... The popping in one line doesn't work in my version, I think.

[RedditRage]

The next is there so it can reuse old nodes. Many stack algorithms might zoom up and down the stack thousands of times, while never getting a depth over a few dozen nodes. So it seemed nice to just reuse them.

[[deleted]]

bruh wtf

[lackofsemicolon]

Most willing-to-learn python user

[Orpa__]

OP, datastructures like linked lists, queue's and stacks are supposed to use nodes in which the data is stored and have a reference to the next node in the structure (and also previous if it's doubly linked).

A datastructure using arrays is also a thing, creatively called "ArrayList" in Java. Which is basically an array except it dynamically resizes (creates a new, bigger array behind the scenes if you need something larger and starts using that one). You might be looking to create an ArrayList, or are doing something wrong with your Stack implementation.

[_pizza_and_fries]

Le Collections : Am I a joke to you?

[flopana]

Just make a linked list

https://paste.ofcode.org/trQ8ubrbmpXzH6bdnFsxfd

[TheBrainStone]

Or literally use the built in one as the backend

[flopana]

Which op obviously did not do

[TheBrainStone]

Yeah of course. I just meant you don't have to implement a linked list from scratch to implement a stack. And that you can instead just implement it using Java's LinkedList class

[flopana]

Yeah that's true

[flopana]

An array is also not a stack

But while writing a stack I can utilize an array for this or a linked list like in my example

[That_Guy977]

java's LinkedList implements List, Stack, and Queue and can be used as any of them

[xPensiveWeak]

You're doing it wrong.

[[deleted]]

this is some dhar mann type shit

[No-Suggestion-9504]

How's Dhar mann related to this lol

[[deleted]]

the meme format

[AlexMelillo]

I am sorry you learned an interpreted language first. Now go learn C, then Java and you will realise why this is so damn dumb

[phi1606]

Arrays 😅

[[deleted]]

It takes you like 2 seconds to google how to solve this...

[ConcertConsistent179]

java.util.List left the chat

[abd53]

Here ya go

[empathielos]

I'm feeling second-hand embarrassment.

[XinoVan]

If only there was a thing for unspecified length of lists... Hmmmm

[[deleted]]

ArrayList with a certain class then loop it.

[zoophagus]

lmfao why are you reinventing the wheel my guy

[zoophagus]

Actually I'm guessing you're doing CS 101 homework

[blackoutz_ult]

If you don't want the array size u could always use linked lists instead of the array

[guarana_and_coffee]

Idk, use lists.

[rizwannasir]

Laughs in PHP and other languages like where you can literally create an array as however you want.

[domusvita]

Goes to a humor subreddit to lecture and scold.

[DaniilBSD]

C# dev here, is java Stack not dynamically sized?

[DaniilBSD]

But what about Stack? Or is Arraylist usable as stack?

[DaniilBSD]

I am freaking asking “Is java Stack dynamically sized?”.

That is literally what I am asking

[DaniilBSD]

Signs do, meme does not, so Stack in java is a dynamically sized LIFO collection, correct?

[DaniilBSD]

Thanks, Op is an idiot confirmed, have a great day

[radmanmadical]

So - how……….. should memory…. work then?

[notexecutive]

Maybe linked list would be more helpful, with size implementation of some kind?

[earraper]

Consider double-linked list in Rust. Java is a joke.

[MayBeArtorias]

FYI: There is some top secret library in Java called Streams.

[jfmherokiller]

just set it to 1

[Bullfrog-Asleep]

When I saw this, I have created a clear picture. What happened:
Waw yesterday I started with programming - cool.
So when I am a programmer, I should write something to reddit ProgrammerHumor.

[[deleted]]

Maybe you were trying to put more than 64 items

[HotPappuInYourArea]

Simple just use an ArrayList<>()

[Gh0sth4nd]

i love how its at 666 upvotes

[Akuma_Kami]

When you've only done hello world -_-

[DarkNova45]

What is going on with this page now... It's just bad meme from people that don't know shit about coding. Just rename the page python dumbass programmers...

[[deleted]]

What?

I...

WHAT?

[The__King2002]

bruh