# block-level scope

```javascript
for (var i = 0; i < 10; i++) {
  /* ... */
}
console.log(i);  // what will this output?
```

should be `undefined` for other languages, but `10` for JS.

## variable hoisting

Variable `i` remains in scope even after the for loop has completed, retaining its last value after exiting the loop.

## `let`

The support for **block-level scopes** is available for the new `let` keyword.