Node.js util.types.isUint8Array() Method

Last Updated : 28 Apr, 2025

The util.types.isUint8Array() method of the util module which is primarily designed to support the needs of Node.js own Internal APIs. It is used to check whether the passed instance in the method is a built-in Uint8Array instance or not.

Syntax:

util.types.isUint8Array( value )

Parameters: This method accepts a single parameter

value that holds any value, i.e instance of any module.

Return value: This method returns a Boolean value, i.e true if the passed value is an instance of Uint8Array otherwise returns

false.

The below examples illustrate the use of util.types.isUint8Array() method in Node.js:

Example 1:

javascript

// Node.js program to demonstrate the    
// util.types.isUint8Array() method 
  
// It includes util module 
const util = require('util'); 
  
// Return false as passed instance is of set 
console.log(util.types.isUint8Array(new Set())); 
  
// Return true as passed instance is of Uint8Array 
console.log(util.types.isUint8Array(new Uint8Array()));

Output:

false
true

Example 2:

JavaScript

// Node.js program to demonstrate the    
// util.types.isUint8Array() method

// It includes util module
const util = require('util');

// Making an instance of Uint8Array
// of size 2
const array1 = new Uint8Array(2);

// Initializing the zeroth element
array1[0] = 42;

// Returns true as passed instance
// is of Uint8Array
console.log(util.types.isUint8Array(array1));

// Making an instance of Uint8Array
const array2 = new Uint8Array([21, 31]);

// Returns true as passed instance
// is of Uint8Array
console.log(util.types.isUint8Array(array2));

// Making an instance of Uint8Array
const array3 = new Uint8Array([21, 31]);

// Making another instance of Uint8Array by
// passing an instance of Uint8Array
const array4 = new Uint8Array(array3);

// Returns true as passed instance
// is of Uint8Array
console.log(util.types.isUint8Array(array4));

// Making an instance of Int16Array of size 2
const array5 = new Int16Array(2);

// Initializing the zeroth element
array5[0] = 10;

// Returns false as passed instance
// is of Int16Array
console.log(util.types.isUint8Array(array5));