Merge increasing arrays

by odiseo

JavaScript

var a = [1, 2, 100, 500];
var b = [0, 1, 1, 3, 200];
var aP = 0;
var bP = 0;
res = [];

while (aP < a.length || bP < b.length) {
    if ( a[aP] < b[bP] )  {
        res.push(a[aP]);
        aP++;

    } else {
        res.push(b[bP]);
        bP++;
    }    
    if(b[bP] === undefined){
         aP++;   
    }
    if(a[aP] === undefined){
         bP++;   
    }    
}

console.log(res);