var let javascript code example
Example 1: javascript var let
// var has function scope.
// let has block scope.
function func(){
if(true){
var A = 1;
let B = 2;
}
A++; // 2 --> ok, inside function scope
B++; // B is not defined --> not ok, outside of block scope
return A + B; // NaN --> B is not defined
}
Example 2: let in javascript
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: 1
Example 3: let javascript
var i = "global";
function foo() {
var i = "local"; // Otra variable local solo para esta función
console.log(i); // local
}
foo();
console.log(i); // global