Question

Basically my mate has been saying that I could make my code shorter by using a different way of checking if an int array contains an int, although he won’t tell me what it is :P.

Current:

public boolean contains(final int[] array, final int key) {
    for (final int i : array) {
        if (i == key) {
            return true;
        }
    }
    return false;
}

Have also tried this, although it always returns false for some reason.

public boolean contains(final int[] array, final int key) {
    return Arrays.asList(array).contains(key);
}

Could anyone help me out?

Thank you.

Answer 1

It’s because Arrays.asList(array) returns List<int[]>. The array argument is treated as one value you want to wrap (you get a list of arrays of ints), not as vararg.

Note that it does work with object types (not primitives):

public boolean contains(final String[] array, final String key) {
    return Arrays.asList(array).contains(key);
}

or even:

public <T>  boolean contains(final T[] array, final T key) {
    return Arrays.asList(array).contains(key);
}

But you cannot have List<int> and autoboxing is not working here.