JavaScript - what is the difference between let and var?

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Created by:

AnnLen

12990

1. Main differences between `let` and `var` keywords are:

let keyword variables do not have variable hoisting.
variable hoisting is shifting variable declarations to top of the source code making them accessible above.

Example 1:

<!doctype html>
<html>
<body>
  <script>

    'use strict';

    a = 2; // variable hosting allows for assigning before declaration
    console.log(a);

    var a;

  </script>
</body>
</html>

Output:

Example 2:

<!doctype html>
<html>
<body>
  <script>

    'use strict';

    var a = 2;
    console.log(a);

  </script>
</body>
</html>

Output:

let keyword variables can be created in different scopes:
let keyword variables var keyword variables
global scope yes yes
function scope yes yes
curly braces scope yes no

	`let` keyword variables	`var` keyword variables
global scope	yes	yes
function scope	yes	yes
curly braces scope	yes	no

2. Tips

ALWAYS use let keyword.

JavaScript - what is the difference between let and var?

1. Main differences between `let` and `var` keywords are:

2. Tips

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1. Main differences between let and var keywords are:

2. Tips

See also

Native Advertising

🚀

Dirask - we help you to

solve coding problems.

Ask question.

❤️💻 🙂

1. Main differences between `let` and `var` keywords are: