# How to Reverse an Integer in Java

## The challenge

Given a 32-bit signed integer, reverse digits of an integer.

Example 1:

```Input: 123
Output: 321```

Example 2:

```Input: -123
Output: -321```

Example 3:

```Input: 120
Output: 21```

Note:
Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231,  231 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

## The solution

``````class Solution {
// take in int, return int
public int reverse(int x) {
// set a Long variable to return
// we make it a long incase we catch the edge case
// of a larger size than int
long out = 0;

// loop while processing
while(x!=0) {
// multiple by 10 and add decimal place division
out = out * 10 + x % 10;
// move the decimal place by 1
x /= 10;
}

// return 0 if edge case found
if (Integer.MAX_VALUE<out || out<Integer.MIN_VALUE) return 0;
// return the output and cast to an int
return (int)out;
}
}
``````