revert.js

var reverse = function(x) {
    let i;
    let y = '';
    let numLen = x.toString().length;
    let firstNum = x.toString().slice(0, 1);
    if (firstNum === '-'){
        y = '-';  
        x = x.toString().slice(1, numLen);
    }
    for(i = numLen; i > 0 ; i--){
       y += x.toString().slice(i-1, i); 
    }
    return y;
};