Variable in for loop is a string [duplicate]

Answer 1

I think you want the values of the array, not the keys. If you can't use ES6, Xorifelse's answer works, but if you can, there is for ... of that works exactly as you probably thought:

for (let i of [1, 2, 3]) {
  console.log(i + 1);
}

There is also Array.prototype.forEach in ES5 and up:

[1, 2, 3].forEach(function(value, index) {
  console.log(value + 1);
});