/**

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

* Note:

* Assume we are dealing with an environment that could only store integers within the 32-bit signed integer range: [−2^31, 2^31 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

*

* Example 1:

* Input: x = 123

* Output: 321

*

* Example 2:

* Input: x = -123

* Output: -321

*

* Example 3:

* Input: x = 120

* Output: 21

*

* Example 4:

* Input: x = 0

* Output: 0

*/

const testValue1 = 123;

const testValue2 = -123;

const testValue3 = 120;

const testValue4 = 0;

/**

* Solution for reversing a number.

* @param {number} num - Number that will be reversed.

* @return {number} Reversed number.

*/

function solution(num) {

if (!isOverflow(num)) {

const reversedNumArray = num.toString().split('').reverse();

if (reversedNumArray[reversedNumArray.length - 1] === '-') {

reversedNumArray.pop();

if (!isOverflow(Number(reversedNumArray.join('')))) {

return Number(`-${reversedNumArray.join('')}`);

}

} else if (!isOverflow(Number(reversedNumArray.join('')))) {

return Number(reversedNumArray.join(''));

}

}

return 0;

}

// maybe write out a solution that doesn't utilize built in methods

/**

* Checks if a number overflows beyond a 32bit integer range.

* @param {number} num - Number to be checked.

* @return {bool}

*/

function isOverflow(num) {

return (num > 2 ** 31) || (num < -(2 ** 31) - 1);

}

console.log(solution(testValue1));

console.log(solution(testValue2));

console.log(solution(testValue3));

console.log(solution(testValue4));