What is the difference between using a let in the body of the for loop and a var specifically in the body of a JavaScript for loop? Do they work differently and why?
Example:
Using let
for (let i = 0; i < 10; i++) {
}
Using var
for (var i = 0; i < 10; i++) {
}
Do these work the same way or differently behind the scenes, does one actually functions better?
Does this difference apply to a while loop and a do-while loop too?
let is block scoped and var is not.
With let, you cannot use i outside the forloop body.
With var (function scoped or globally scoped) you can.
for (var j = 0; j < 10; j++) {
}
console.log(j);
for (let i = 0; i < 10; i++) {
}
console.log(i);You can run the for loop with var in your chrome console, and will see that i has been attached to the window object.