Arrays.copyOfRange()

I didnt even know that method existed (Java 6 only).

http://java.sun.com/javase/6/docs/api/java/util/Arrays.html

Why is this method (and its 10 variants - 20 if you count CopyOf) even necessary?

It does exactly the same thing as System.arraycopy

except that it creates a new array instead of being passed one.

At most that saves you one line of code (a new array initialization).

int[] source...;

int[] target...;

System.arraycopy(source, 0, target, 0, source.length);

vs

int[] source...;

int[] target = Arrays.copyOfRange(source, 0, source.length)

Isnt this just bloating the API for no good reason at all?

I mean all theyve done is make 10 copies of a method that already exists.

TuringPesta at 2007-7-10 12:08:18 >

TuringPest:

I meant using the following method:

static <T,U> T[] copyOfRange(U[] original, int from, int to, Class<? extends T[]> newType)

This method is great. It instantiates a new array, copies elements to it, and controls the destination array type. No existing method provide all this.

DrClap:

I simply need to create an array of type T (known at runtime). So the class passed could be String[].class, Integer[].class, Object[].class, ... etc. I tested it with hardcoding the type and it worked.

I think the problem is with the syntax rather than the relationship between the class object and T[] because I am getting a compilation error not a runtime error.

Gen.Javaa at 2007-7-10 12:08:18 >