Node.js – util.types.isAsyncFunction() Method

The util.types.isAsyncFunction() checks whether the passed value is an async function or not. If the above condition holds, it returns True, else False.

Syntax

util.types.isAsyncFunction(value)

Parameters

It takes only one parameter −

• value − This input value takes input for the required parameter and checks if it is an async function or not.

It returns True or False based upon the input value passed.

Example 1

Create a file with the name "isAsyncFunction.js" and copy the following code snippet. After creating the file, use the command "node isAsyncFunction.js" to run this code.

// util.types.isArgumentsObject() Demo Example

// Importing the util module
const util = require('util');

// Passing empty function to check if its async
console.log("1. " + util.types.isAsyncFunction(function f() {}));

// Passing empty async function to check
console.log("2. " + util.types.isAsyncFunction(async function f1() {}));

Output

C:\home
ode>> node isAsyncFunction.js
1. false
2. true

Example 2

// util.types.isArgumentsObject() Demo Example

// Importing the util module
const util = require('util');

// An async function
async function myFunction() {
   console.log("Async function - Welcome to TutorialsPoint");
}

// An async/await function
async function fun1() {
   const result = await 1;
   console.log("Await function");
}

// Passing async function to check if its async
console.log("1. " + util.types.isAsyncFunction(myFunction()))

// Passing async + await function
console.log("2. " + util.types.isAsyncFunction(fun1()))

Output

C:\home
ode>> node isAsyncFunction.js
Async function - Welcome to TutorialsPoint
1. false
2. false
Await function