JavaScript Instanceof Operator (original) (raw)

Last Updated : 27 Dec, 2023

The **instanceof operator in JavaScript is used to check the type of an object at run time. It returns a boolean value if true then it indicates that the object is an instance of a particular class and if false then it is not.

**Syntax:

let gfg = objectName instanceof objectType

**Parameters:

• **objectName: States the name of the Object.

**Return Value: This method returns a boolean value if true then it indicates that the object is an instance of a particular class and if false then it is not.

**Example 1: Below is the example of the Instanceof Operator.

html `

GeeksforGeeks

Instanceof Operator.

<p id="GFG"></p>

<script>
    let a = ["Geeks", "for", "Geeks"];

    document.getElementById("GFG").innerHTML =
        (a instanceof Array) + "<br>" +
        (a instanceof Number);
</script>

`

**Output:

JavaScript Instanceof Operator

**Example 2: Below is the example of the Instanceof Operator.

html `

GeeksforGeeks

Instanceof Operator.

<p id="GFG"></p>

<script>
    let fruits = ["Apple", "Mango", "Banana"];

    document.getElementById("GFG").innerHTML =
        (fruits instanceof Array) + "<br>" +
        (fruits instanceof Object) + "<br>" +
        (fruits instanceof String) + "<br>" +
        (fruits instanceof Number);
</script>

`

**Output:

JavaScript Instanceof Operator

**Example 3: Demonstrating that String and Date objects are also a type of Object (derived from Object).

JavaScript `

`

**Output:

true
false
true
true
true
false

We have a complete list of Javascript Operators, to check those please go through the Javascript Operators Complete Reference article.

**Supported Browsers:

• Google Chrome
• Firefox
• Edge
• Opera
• Apple Safari