JavaScript Keywords

Written by Swapnil RajaPublished 15 Jul 2026

JavaScript keywords are reserved words that have a special meaning in JavaScript.

These words are already used by JavaScript for specific tasks, so you cannot use them as variable names, function names, or object names.

Example

javascript

let name = "Amit";

Here, let is a JavaScript keyword. It is used to declare a variable.

What are Keywords?

Keywords are special words that JavaScript understands.

Each keyword has a fixed purpose.

Example

javascript

PreviousJavaScript Expressions NextJavaScript Identifiers

if (age >= 18) {
  console.log("You are eligible.");
}

Keyword	Use
`<code>`if`</code>`	Checks a condition

Keyword	Use
`<code>`let`</code>`	Declares a variable
`<code>`const`</code>`	Declares a constant variable
`<code>`var`</code>`	Declares a variable
`<code>`if`</code>`	Starts a condition
`<code>`else`</code>`	Runs code when condition is false
`<code>`switch`</code>`	Checks multiple cases
`<code>`case`</code>`	Defines a case inside switch
`<code>`break`</code>`	Stops a loop or switch
`<code>`for`</code>`	Starts a for loop
`<code>`while`</code>`	Starts a while loop
`<code>`function`</code>`	Defines a function
`<code>`return`</code>`	Returns a value from a function
`<code>`class`</code>`	Defines a class
`<code>`new`</code>`	Creates a new object
`<code>`try`</code>`	Tests a block of code
`<code>`catch`</code>`	Handles errors
`<code>`import`</code>`	Imports code from another file
`<code>`export`</code>`	Exports code to another file

Keyword	Use
`<code>`function`</code>`	Creates a function
`<code>`return`</code>`	Sends a value back from the function

Complete Example

html

<!DOCTYPE html>
<html>
<head>
  <title>JavaScript Keywords</title>
</head>
<body>

  <h1>JavaScript Keywords</h1>

  <p id="result"></p>

  <script>
    let age = 20;
    let message;

    if (age >= 18) {
      message = "You are eligible.";
    } else {
      message = "You are not eligible.";
    }

    document.getElementById("result").innerHTML = message;
  </script>

</body>
</html>

JavaScript Keywords

Example

What are Keywords?

Common JavaScript Keywords

Keywords for Variables

Keywords for Conditions

Keywords for Loops

Keywords for Functions

Keywords Cannot Be Used as Names

Complete Example

Try It Yourself

Important Points

Conclusion