The goal is supposed to return the reverse of an integer as long as it's smaller than 2^31-1(32-bit integers) here is the code:

var reverse = function(x) {
    let limit=Math.pow(2,31)-1;
    let r=[];
    while(x!=0){
        r.push(x%10);
        x=x%10;
    }
    let a=0;
    let n=0;
    while(r){
        a=a+r.pop()*Math.pow(1,n);
        n++;
    }
    return a<=limit ? a : 0;
    
};