Remove Null Value from String array in java

Question

How to remove null value from String array in java?

String[] firstArray = {\"test1\",\"\",\"test2\",\"test4\",\"\"};

I need the \"firstArra

Answer 1

Those are zero-length strings, not null. But if you want to remove them:

firstArray[0] refers to the first element
firstArray[1] refers to the second element

You can move the second into the first thusly:

firstArray[0]  = firstArray[1]

If you were to do this for elements [1,2], then [2,3], etc. you would eventually shift the entire contents of the array to the left, eliminating element 0. Can you see how that would apply?

Answer 2

A gc-friendly piece of code:

public static<X> X[] arrayOfNotNull(X[] array) {
    for (int p=0, N=array.length; p<N; ++p) {
        if (array[p] == null) {
            int m=p; for (int i=p+1; i<N; ++i) if (array[i]!=null) ++m;
            X[] res = Arrays.copyOf(array, m);
            for (int i=p+1; i<N; ++i) if (array[i]!=null) res[p++] = array[i];
            return res;
        }
    }
    return array;
}

It returns the original array if it contains no nulls. It does not modify the original array.