Variables in JavaScript: var, let, and const

Variables in JavaScript

Keywords: JavaScript variables, var let const, JavaScript basics

What are Variables?

Variables are containers that store data for later use.

Example:

javascriptCopyEditlet name = "Ali";
const age = 25;
var country = "Pakistan";

Three Ways to Declare Variables

Variable Scope

• Global Scope – Accessible anywhere in code
• Local Scope – Accessible only inside a function
• Block Scope – Accessible only within {}

Example:

javascriptCopyEdit{
  let blockVar = "Inside Block";
  console.log(blockVar);
}
// console.log(blockVar); // Error

Hoisting

JavaScript moves var declarations to the top before execution, but let and const are not accessible before YouTube declaration.

Best Practices

• Always use const unless the value changes
• Use meaningful names like userAge instead of x
• Avoid var in modern code
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