How to remove null element from int array (Java)?

As we know, primitive types are not object in java, for them there are overloaded stream()method in Arrays class. Suppose here just consider int. If we pass int[] then stream(int[] array) getting called and returns IntStream object. If you go and see IntStream class then you will find only one toArraymethod, which doesn't accepting any arguments.

So, we can't do toArray(int[]::new).

int[] in1 = {0, 0, 2, 0, 3}; int[] in2 = Arrays.stream(in1).filter(x -> x != 0).toArray();

But for any Reference type array, we can convert to specific type. e.g

String[] str2 = {"a","b",null,"c"};
    String[] strArr = Arrays.stream(str2).filter(i -> !=null).toArray(String[]::new);
    for (String string : strArr) {
        System.out.println(string);
    }

In the Reference type case, a generic stream method gets called from Arrays class and produces Stream<T>, now Stream interface has two overloaded toArray(). If we use

1. toArray() then yield Object[], in this case we need to caste.
2. toArray(IntFunction<A[]> generator) then give us A[], where A is any reference type.

See below example

package test;
import java.util.Arrays;
public class EliminateZeroFromIntArray {
public static void main(String[] args) {

    int[] in1 = {0, 0, 2, 0, 3};
    int[] in2 = Arrays.stream(in1).filter(x -> x != 0).toArray();
    for (int i : in2) {
        System.out.println(i);
    }

    String[] str = {"a","b",null,"c"};
    Object[] array = Arrays.stream(str).filter(i -> i !=null).toArray();

    for (Object object : array) {
        System.out.println((String)object);
    }

    String[] str2 = {"a","b",null,"c"};
    String[] strArr = Arrays.stream(str2).filter(i -> i !=null).toArray(String[]::new);
    for (String string : strArr) {
        System.out.println(string);
    }
}

}

This probably isn't the best version of this you'll find but:

private int[] removeZeros(int[] array, int toRemove)
    {
        int count = 0;
        int arrayLength = array.length;

        for (int i = 0; i < array.length; i++)
        {
            if (array[i] == toRemove)
                count++;
        }

        int[] newArray = new int[arrayLength - count];
        int j = 0;
        for (int i = 0; i < array.length; i++)
        {
            if (array[i] != toRemove)
            {
                newArray[j] = array[i];
                j++;
            }
        }
        return newArray;
    }