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var 语句用于声明一个函数作用域或全局作用域的变量，并且可以选择将其初始化为一个值。

A variable is a “named storage” for data. We can use variables to store goodies, visitors, and other data.

Variables are Containers for Storing Data JavaScript Variables can be declared in 4 ways: Automatically Using var Using let Using const

Learn why we use var, let and const and what would happen if we didn't use them. We explore declaring variables, the global object, the call stack, function execution contexts and more.

let 声明用于声明可重新赋值的块级作用域局部变量，并且可以选择将其初始化为一个值。

Where a variable acts a container of data with the ability of being change any time during the course of a program, a constant is its complete opposite.

const 声明用于声明块作用域的局部变量。常量的值不能通过使用赋值运算符重新赋值来更改，但是如果常量是一个对象，它的属性可以被添加、更新或删除。

在读完之前的一些文章之后，你现在应该大概知道了 JavaScript 是什么，你能用它干什么，它是怎么跟其他 web 技术协同工作的，以及从上层来看，它有哪些主要特性。在本文中，我们将深入了解真正的基础知识，学习如何使用 JavaScript 最基础的构建单元——变量。

JavaScript 提升是指解释器在执行代码之前，似乎将函数、变量、类或导入的声明移动到其作用域的顶部的过程。

A quick and painless description of JavaScript Hoisting

JavaScript Simplified CourseIn this video I will be explaining everything you need to know about hoisting so next time someone mentions it you can understand exactly what they mean.

Learn the specifics behind the three things involved in scripting with variables: creating (or declaring) variables, assigning values to those variables, and including the variables in other statements in your code.

A variable name should accurately identify your variable. When you create good variable names, your JavaScript code becomes easier to understand and easier to w

Introduction to JavaScript Naming Conventions for differen data types and data structures in JS. Learn more about how to name private methods, global vairbales, or a constant variable ...

Please note: This guide is no longer being updated. Google recommends migrating to TypeScript, and following the TypeScript guide.

Scope determines the accessibility (visibility) of variables. JavaScript variables have 3 types of scope: Block scope Function scope Global scope

These are notes based on my Beginner JavaScript Video Course. It's a fun, exercise heavy approach to learning Modern JavaScript from scratch.

In this video we'll compare the keywords var, let, and const in JavaScript which also requires an understanding of JavaScript scopes such as global scope, local scope, function scope, and block scope.

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Var vs Let vs Const