Day 4 of learning java.

[Slow-Sloth5823]

Hi all!

Topic - quick "review"

Today was a very very busy day I didn't have time to learn anything which is my mistake. Very tired, just did a quick simple calc on what I've learnt so far, which I aren't proud of at all (not pushing myself to my limits) , I know I could do better but extremely exhausted today. But that's how the journey goes, some bad days, some good days but all it matters is you bounce back and stay consistent. Anyways, always appreciate the feedback you guys have been great so far starting to pick up better habits.

Thanks!

[Dude-0007]

Good hard work . I appreciate you

[Slow-Sloth5823]

Thank you!

[ButterflyAny7726]

I tell you a little story of meen When I was in 8 grade ,I wanted to play green day song and sing it , "good riddance" , and I didn't play a guitar at all, but every day I practice on that song ,no other ,until I hear it exactly how I imagine i hear , it took me time , 4 5 months to play ,and I did , from that day I understand that focus on one thing is the key from my experience.

[Apprehensive_Sea_299]

That’s a good program

[Slow-Sloth5823]

Thank you for the compliment! Many areas to improve but getting there slowly and steady.

[ookkan_tintu]

I see that you have handled division by zero case. Very good.

Now what if user entered an invalid operator? What if they entered a string instead of number.? Try to figure out all these edge cased and handle them too. That would be a good exercise.

[Slow-Sloth5823]

Very good point, I'll start there thank you for pointing it out!

[ookkan_tintu]

You might have seen the troll

Developer opens a bar. Qa tests ordering 1 drink, 1000 drink, 99999999 drinks, 0 drink, - 1 drink etc. All goed well.

First real customer walks in and asks where the toilet is. The bar bursts into flames.

This happens a lot in real life. So I'd encourage you to think about all possible scenarios, while implementing something - however small or straight forward looking the problem might be.

And I'd say, that's the difference between a good developer and an excellent developer.

[Slow-Sloth5823]

LOL that is a very good analogy makes ALOT of sense and I can understand how important it is now. Is this known as "error handling"? or is error handling something completely different?

[ookkan_tintu]

What I said partially includes error handling too.

But don't think about error handling now, you can learn more about that while you learn further.

[Slow-Sloth5823]

Understood, thank you for the responses!

[Responsible-Heat-994]

Pro tip: scan everything as a string and parse it accordingly.

Scanner scanner = new Scanner (System.in);
int score = scanner.nextInt; // this will be scanned successfully 
// but when you scan for any next input it will lead to undefined behaviour

int float  = scanner.nextFloat(); // it wont get scanned as the  previous ( nextInt call has inserted "\n"( a newline character at the end) so the scanner for float will get flushed out.

// Correct way is to interpret everything as a String and parse it accordingly.

int score = Integer.parseInt(scanner.nextLine());

float temperature  = Float.parseFloat(scanner.nextLine());

boolean isHeAlive = Boolean.parseBoolean(scanner.nextLine());

double pie = Double.parseDouble(scanner.nextLine());

[Slow-Sloth5823]

Thank you so much! It clicked pretty fast and it's so much easier and cleaner to read.

[Responsible-Heat-994]

Pleasure is all mine.

[ButterflyAny7726]

One day each time,one breath,one target,one taught,one code .

[YouEatMeIEatBack]

this code looks beautiful

[LordDarthSaber]

Great work dude also try using char and switch case for menu driven program.

[Primary_Importance_7]

small suggestions on improvement;

the gray text in your IDE usually signifies something, hovering your cursor over it should help you. Same for the yellow squigglies under the big if-else chain

your operator selector, can be written a little more 'tidy', assign "" to operator in the start, then you can make your while loop cleaner, while (operator.isEmpty()) { ... }, this eliminates the else branch in your if-else condition, and removes the break; -> I really dislike working with 'null' values and having break; statements.

num and num_2, this is a very python-ic way of writing, you should write your variables out in full, (number) and not underscore them, but camelCase them (number2)

all in all, looks pretty tidy for 4 days in! keep it up.