-Shift all non-zero numbers to the left replacing all zero positions.

-Keep count of all the zeros on the way.

-Place zeros in the back of the array.

```
public class Solution {
public void moveZeroes(int[] nums) {
int currentIndex = 0, zeroCount = 0;
for(int i = 0; i < nums.length; i++) {
if(nums[i] != 0) nums[currentIndex++] = nums[i];
if(nums[i] == 0) zeroCount++;
}
for(int i = nums.length-zeroCount; i < nums.length; i++) nums[i] = 0;
}
}
```