Convert string array to integer array

var res = ['2', '10', '11'].map(function(v) {
  return parseInt(v, 10);
});

document.write('<pre>' + JSON.stringify(res, null, 3) + '<pre>')

More simplified ES6 arrow function

var res = ['2', '10', '11'].map(v => parseInt(v, 10));

document.write('<pre>' + JSON.stringify(res, null, 3) + '<pre>')

Or using Number

var res = ['2', '10', '11'].map(Number);

document.write('<pre>' + JSON.stringify(res, null, 3) + '<pre>')

Or adding + symbol will be much simpler idea which parse the string

var res = ['2', '10', '11'].map(v => +v );

document.write('<pre>' + JSON.stringify(res, null, 3) + '<pre>')

FYI : As @Reddy comment – map() will not work in older browsers either you need to implement it ( Fixing JavaScript Array functions in Internet Explorer (indexOf, forEach, etc.) ) or simply use for loop and update the array.

Also there is some other method which is present in it’s documentation please look at Polyfill , thanks to @RayonDabre for pointing out.