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[Skyrunner]

Java in data structures class makes me so frustrated so much needless typing...

Can I have my C# please?

[TheBiggerFish]

Define 'needless'?

[Skyrunner]

For one, the "one public class per file" rule struck me as being arbitrary.

The only real example of needless boilerplate I can think of is this:

ClassName thing = new ClassName();

C# lets you do this:

var thing = new ClassName();

It's a big help for long classnames, plus it's actually still statically typed since "var" can be inferred to be ClassName at compiletime, plus if you want a different polymorphic type just say so.

It would be much better if the IDE I was using was better at intellisense, but alas.

edit:

I also don't like that they didn't overload the String class's [] operator, have to use charAt() instead. And no == overloading, gotta use .equals()...

[TheBiggerFish]

Eh?
You can declare more than one class per file IIRC.

But it's a good thing to do in any case.

[Reelya]

The only real example of needless boilerplate I can think of is this:

ClassName thing = new ClassName();

That seems a bit trivial in the typing sense. A quick ctrl-c/ctrl-v gets that almost as quick as typing "var" would. Plus it's much less flexible: if you want to split up declaration and initialization then you have additional work to do to get rid of the "var" keyword. In other words, savings 0.1 seconds of typing but makes things a pain in the ass later for maintenance.

[Skyrunner]

ClassName thing = new ClassName();

Isn't "needless" ... because of polymorphism. In c++, the "new" keyword can assign any type to the pointer variable on the left, so the two types don't necessarily have to be the same, and you'd want to be able to specify that.

Not comparing to C++ but C#, which seems to do perfectly fine at deducing the type from the variable. if you want a base class, you would have to specify the base class, but the rest of the time you can use var and everything goes fine.

[Reelya]

var is sloppy - would not recommend for any serious usages. Saving 0.1 seconds of typing isn't work extra headaches later on working out what types things actually are.

Sure it can make code "cleaner" by removing context, but that doesn't necessarily translate to good maintainable code.

[Rose]

I often use var at first, when quickly typing something out, and then go back and replace it.

[Skyrunner]

In the end, it's mostly my IDE's fault for not doing intellisense properly :v

[i2amroy]

What I find is the best place for var/auto is in loops. In that case not being able to see instantly what type it is doesn't hurt you quite as much because the important part is already non-visible because it's linked to the object that you are iterating through. And it provides some benefits in that if you ever need to update the type of the object that you are iterating (for example going from an array to a vector, or some such, or making the objects stored inside of it go from a single object to a bundled struct) then it can save you a lot on refactoring every single mention of it.

This is not to say, of course, that you should be abusing the auto keyword everywhere, or even in every loop. It just goes to show that, IMO, there are places where it certainly is useful in providing enough benefits to outweigh the fact that the type of an object isn't immediately apparent at the first glance. (It's also useful for cases where you have very complex data structures holding the things you care about, like a dictionary of vectors of arrays or something similar, since it can eliminate a huge amount of extra typing in those cases with all of the "::iterator" stuff you need to throw on the end).

[TheBiggerFish]

The only real example of needless boilerplate I can think of is this:

ClassName thing = new ClassName();

That seems a bit trivial in the typing sense. A quick ctrl-c/ctrl-v gets that almost as quick as typing "var" would. Plus it's much less flexible: if you want to split up declaration and initialization then you have additional work to do to get rid of the "var" keyword. In other words, savings 0.1 seconds of typing but makes things a pain in the ass later for maintenance.

Er, I didn't say that.

[Vattic]

I am failing to understand a bit of found code that takes the aspect ratio and area of a rectangle and returns the width and height. I wondered if anyone else might be able to explain. I suspect this is a basic maths fail on my part.

Spoiler (click to show/hide)

For examples sake lets say the area = 150 and the ratio = 1.5.

Code: [Select]

height = sqrt(area / ratio)
       = sqrt(150 / 1.5)
       = sqrt(100)
       = 10

width = area / height
      = 150 / 10
      = 15
I don't understand why the above works. On paper I'd do it like:

Code: [Select]

width * height = area
3x * 2x = 150
   6x^2 = 150
    x^2 = 150/6
        = 25
      x = sqrt(25)
        = 5

width = 3x
      = 3 * 5
      = 15

height = 2x
       = 2 * 5
       = 10
For the curious I'm dividing a rectangle into a grid so that a given number of elements will fit one per cell. In the above I replace area with desired number of elements to fit and round up to make sure I always have space, even if it leaves some cells empty.

[TheBiggerFish]

Well, how do you calculate aspect ratio?

[Vattic]

width / height.

[TheBiggerFish]

Well there's your answer.  I think.