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Today, the editor will share with you the relevant knowledge points about how to use the JavaScript block scope. The content is detailed and the logic is clear. I believe most people still know too much about this knowledge, so share this article for your reference. I hope you can get something after reading this article. Let's take a look at it.

JavaScript block level scope (Block Scope)

Variables declared with the var keyword do not have block-level scope and can still be accessed outside {}.

{

Var x = 2

}

/ / you can use the x variable here

Before ES6, there was no concept of block-level scope.

ES6 can use the let keyword to achieve block-level scope.

The variables declared by let are only valid within the code block {} where the let command is located and cannot be accessed outside {}.

{

Let x = 2

}

/ / the x variable cannot be used here

These are all the contents of the article "how to use JavaScript Block scopes". Thank you for reading! I believe you will gain a lot after reading this article. The editor will update different knowledge for you every day. If you want to learn more knowledge, please pay attention to the industry information channel.

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