
**Access variables** defined in the **current function's
scope** and the **scope of any parent function** or the global scope.
  

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### Which variables are accessible from the comment?

~~~javascript
let foo = 1;

function outer() {
  let bar = 1;

  function innerA() {
    let baz = 1;
  }

  function innerB() {
    let qux = 1;

    // which variables are accessible here?
  }
}
~~~
    


### What is printed to the console?

~~~javascript
function remember(secret) {
  return function () {
    console.log(secret);
  }
}

const sayA = remember('foo');
const sayB = remember('bar');

sayA();
sayB();
~~~
    


### What is printed to the console?

~~~javascript
let secret;

function remember(arg) {
  secret = arg;

  return function () {
    console.log(secret);
  }
}

const sayA = remember('hello');
const sayB = remember('world');

sayA();
sayB();
~~~
    


### What is printed to the console?

~~~javascript
let i = 0;

for (i = 0; i < 3; i++) {
  setTimeout(() => {
    i++;
    console.log(i);
  }, 0);
}
~~~
    


~~~javascript
for (const i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 0);
}
~~~
        


~~~javascript
for (let i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 0);
}
~~~
        


~~~javascript
for (var i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 0);
}
~~~
        


~~~javascript
let i;

for (i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 0);
}
~~~
        


### Which snippets output the following to the console?

~~~
3
3
3
~~~

Pay close attention to usage of `const`, `let`, and `var`.
    

Closures

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