How to count in Java the trailing zeros from an Integer? (Ex: 234000 => 3 zeros)

Question

The title is pretty much self explanatory. :)

1232 => 0
1231030 => 1
2000 => 3
34444400000 => 5

Answer 1

If it fits into an int/long, just check if the number modulo 10 is 0 and keep a counter:

long x = ...
if (x == 0) {
    return 0;
}
int counter = 0;
while (x % 10 == 0) {
    counter++;
    x /= 10;
}

If it's too big to fit in long, store it in a String and count zeroes from the last char:

String s = ...
int counter = 0;
while(counter < s.length() && s.charAt(s.length() - 1 - counter) == '0') {
    counter++;
}

Answer 2

Integer class has an inbuilt function to count the trailing zeros. javadocs

int trailingZeroes = Integer.numberOfTrailingZeros(int i);