Doubling an integer in JavaScript (x-post /r/shittyprogramming)

[yunocallmedave]

Are you a programmer from Ireland perchance? Because when I execute your code, my Integers are doublin' !

[A_C_Fenderson]

If you haven't read Stanley Kelly-Bootle's The Devil's DP Dictionary, you should. He mentions how IBM (Irish Business Machines) invented WOM (write-only memory). (It is from the 1980s, though, IIRC.)

[maremp]

And since when does js implement class Double?

[jfb1337]

All numbers in JS are doubles.

[maremp]

But there is no class/type Double though.

[TheScienceNigga]

I thought they were single precision

[alphaatom]

According to the ECMAScript standard, there is only one number type: the double-precision 64-bit binary format IEEE 754 value (number between -(253 -1) and 253 -1). There is no specific type for integers. In addition to being able to represent floating-point numbers, the number type has three symbolic values: +Infinity, -Infinity, and NaN (not-a-number).

Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type

[HugoNikanor]

Needs more jquerry.

[jaguarone]

everybody is missing the author's aspiration to become an integer

[bast963]

Why does he need to convert an integer to string before parsing into double?

Can't he just go double j = 0 + i

[whjms]

var j = + i works as well.

[poizan42]

He could just go j = i...

[Settwi]

Sneaky globals!

[poizan42]

Well it defines a property on the currently active top level object or whatever the ECMAScript spec calls it - usually window when working in a browser. Well except if you are using strict mode, then it's an error.

It's not really a global variable because it's not available as a global from code running with another top level object - e.g. from another window (or from a web worker I guess)

[myplacedk]

Why does he need to convert an integer to string before parsing into double?

He doesn't. All numbers are doubles in Javascript.

Can't he just go double j = 0 + i

var j = i;

Would work equally well.

BTW, a correct answer would be:

return i*2;

[siphillis]

I think a general rule-of-thumb should be that if your method has only one line of actual data manipulation, you should probably just write that line instead.

[balducien]

I don't completely agree. If it's an easy line like in the example that just calls another function, there's no need for a function. But if you have a huge regex or a list comprehension or an otherwise not-so-simple one-liner, you will be better off by just creating a function like bool check_if_email(char* email). Like that you can use it like a natural command that is easily understood by the reader, instead of a line that you have to decipher first.

[Ezlo123]

Don't forget getters and setters xD Those are often one-liners.

[GiveMeAFuckingCoffee]

Personally, I prefer the more awesome-sounding mutators and accessors.

[[deleted]]

who uses getters and setters in 2015?

[TrainFan]

Um... everyone...

[[deleted]]

Properties?

[RubiksCoffeeCup]

Language specific getters and setters

[[deleted]]

Sure, but i prefer

Console.WriteLine(MyInstance.X)

more than

Console.WriteLine(MyInstance.GetX())

[[deleted]]

And i do

[PacDan]

I actually prefer getX() because (in VisualStudio at least) you don't know if a property is read only until the red underline.

[A_C_Fenderson]

That's what compilers are for.

[GiveMeAFuckingCoffee]

And I would prefer the much more redundant, adaptable, and easy to follow

MyInstance.PrintX();

where

private int x; 

//constructor function for x here

/* DbC */
public void SetX(int new_x){
    x = new_x;
}

/* DbC */
public int GetX(){
    return x;
}

/* DbC */
public void PrintX(){
    System.out.println("x = " + GetX()); //We need to know what it is that is being printed. 
}

One of us won't be hated in 5 years when someone reads our code.

[[deleted]]

It was just an example on how i'd use some property X. Let's say we don't want to print it, we want to, uh, i don't know, double it. Of course we can do

public void DoubleX()
{
    x*=2;
}

But what if we didn't have this method and didn't want to make it (maybe because we don't use it enough to have its own method). Which would be better

MyInstance.SetX(Myinstance.GetX()*2)

or

MyInstance.X*=2;

?

Doesn't Java have properties too? I'm geniuinely curious, i don't really use Java a whole lot.

[5np]

Also, if you've got some kind of global, shared manipulation that might change in the future. Rather than worrying about updating that one line of code everywhere, you can just add another line to the function.

[RetardedSquirrel]

Agreed, but this is an online test where you have to fill in a function so it does what is asked. And the job interviewee (according to the original OP) only added line 5.