let in javascript

JavaScript
let: //only available inside the scope it's declared, like in "for" loop, 
var: //accessed outside the loop "for"The let statement declares a block scope local variable, optionally initializing it to a value.

let x = 1;

if (x === 1) {
  let x = 2;

  console.log(x);
  // expected output: 2
}

console.log(x);
// expected output: 1var i = "global";
function foo() {
    var i = "local"; // Otra variable local solo para esta función
    console.log(i); // local
}
foo();
console.log(i); // globallet /*Var name*/ = /*what is equals*/
Source

Also in JavaScript: