Programming, computers, etc. [Serious]

[dewero]

Oh... Reading the context in the documentation makes it a little more clear.

public final Buffer clear()

Clears this buffer. The position is set to zero, the limit is set to the capacity, and the mark is discarded.

Invoke this method before using a sequence of channel-read or put operations to fill this buffer. For example:

buf.clear(); // Prepare buffer for reading
in.read(buf); // Read data

This method does not actually erase the data in the buffer, but it is named as if it did because it will most often be used in situations in which that might as well be the case.

buffer.clear simply "resets" the buffer, and doesn't actually "clear" the buffer in the sense that data in the buffer is deleted. From what I read, it doesn't seem like it would affect normal coding too much, but then again, programmers like to do funny things.

[Anonymously Famous]

Sometimes resetting the buffer might be useful.

[atomtengeralattjaro]

meh. okay then.

today i continue fiddling around in java networking.

[Anonymously Famous]

I wish you luck.

[dewero]

I strongly dislike networking. Maybe that's because I've never done anything with it before

[Anonymously Famous]

I really appreciate those who understand and use it in their programming, because I like to use the Internet, and that's all about networking.

[ThingerDudes]

had to make a server thing with sockets and encryptions and forking and crap for a project last year. Really really annoying. But fun once you get it working.

[Anonymously Famous]

Yeah. It sounds really annoying.

[atomtengeralattjaro]

had to make a server thing with sockets and encryptions and forking and crap for a project last year. Really really annoying. But fun once you get it working.

what language/platform did you make it in/on?

[ThingerDudes]

We had to do it in C. seg faults...so many seg faults...
and do documentation on it which was worth half the grade...
yeah...it was not a fun course.

[Anonymously Famous]

Writing documentation is a good skill to have.

[atomtengeralattjaro]

[continuing from the daily thread]

it occured to me that a 2-dimensional array is not the same as an array of arrays, because in the latter, you might be able to add arrays of varying size to an array of arrays, as opposed to a 2D array, which has only 2 dimensions.

a.)

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X X X X X X X X
X X X X X X X X
X X X X X X X X
X X X X X X X X

b.)

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X X X X
X
X X X X X X X X X X X
X X X X X X X X

i just checked, and it turns out java's syntax in arrays differs from C# in the following way:

java:

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        int[][] a = new int[3][2]; //okay (2D array, not an array of arrays)
        a[0][0] = 1; //cool
        a[0,0] = 1; //not cool
        
        int[,] c; //doesn't compile
        
        int[][] b = new int[3][]; //okay (a 3 sized array of integer arrays)
        b[0] = new int[2]; //okay (let the first element in the 3-sized array be a 2-sized int array)
        b[0][1] = 1; // let the second element of the first element of the b array be 1.

however, in C#:

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            int[,] a = new int[2, 2]; // okay
            a[0, 1] = 87; //okay
            a[0][1] = 44; //wrong

            int[][] c = new int[3][2]; //NOT okay

            int[][] b = new int[3][]; //okay (a 3 sized array of integer arrays)
            b[0] = new int[2]; //okay (let the first element in the 3-sized array be a 2-sized int array)
            b[0][1] = 1; // let the second element of the first element of the b array be 1.

Conclusion: double brackets like this: [][] are the only way to create a 2D array in Java, and are also able to create an array of arrays, but they only mean an array of arrays in C#.
also, accessing 2D arrays in Java is not possible with the C# syntax [,] and [2,3]
and accessing 2D arrays in C# is not possible with the Java syntax [2][3].


it's not all that complicated, i just kinda overcomplicated it, but i wanted to see how they really differ, because i've always thought the syntax of C# and Java are very similar on this basic level. Apparently not.

[Anonymously Famous]

Oh, they're similar, just not exactly the same. On a conceptual level, a 2d array is just an array of arrays with the lengths enforced. There are several languages where 2d arrays aren't explicitly possible - You have to enforce the lengths yourself. This can be tricky in languages that have arrays of modifiable length, like the Python list. Just do a myGrid.append(x) and you've messed up your 2d array.

Of note: Last week, for the first time in my memory, I had a problem in which a 3d array made sense (more accurately, a Python dictionary (named array) of lists of lists).

[atomtengeralattjaro]

ha, stacking dimensions is fun
are you saying that there are no real arrays in python?
It is my understanding that arrays (and i mean real arrays, forced and fixed) are good because it is extremely easy for the computer to index them in the memory. All it needs to do is get the address of the beginning, and then add the length of an item, times the index requested. If there are structs in the array, they all have the same length, and if there are objects, it's only their reference stored there anyway, and those are of the same length too. As opposed to lists, where you'd need to step through a bunch of them in different places just to get to the n'th element.

[Anonymously Famous]

Python types can change on a whim, and Python lists don't enforce type. There is an array class that enforces type, and it's more memory efficient than lists, but it doesn't have fixed size.

[dewero]

Oh the woos of a dynamic language...

[Anonymously Famous]

I like dynamic languages.

[klinscy]

Dynamic = more complicated???

[Anonymously Famous]

Nope. Not as efficient, but you don't need to declare types or initiate variables usually.

a = "2"
a = int(a)

No error, because the type can change.

Also, Python and some other related languages can have multiple return values from functions, which I think is cool.

[atomtengeralattjaro]

multiple return values from functions

now THAT would be a good thing even in non-dynamic languages. Anytime I have to give multiple results, i need to use out parameters or wrap them in some class. How does it work in python? i mean how do you invoke a method that has multiple return parameters, where do you put the results?