JavaScript: Check if a given argument is a number
JavaScript fundamental (ES6 Syntax): Exercise-195 with Solution
Write a JavaScript program to check if a given argument is a number.
- Use typeof to check if a value is classified as a number primitive.
- To safeguard against NaN, check if val === val (as NaN has a typeof equal to number and is the only value not equal to itself).
Sample Solution:
JavaScript Code:
//#Source https://bit.ly/2neWfJ2
const isNumber = val => typeof val === 'number';
console.log(isNumber('1'));
console.log(isNumber(1));
Sample Output:
false true
Pictorial Presentation:
Flowchart:

Live Demo:
See the Pen javascript-basic-exercise-195-1 by w3resource (@w3resource) on CodePen.
Improve this sample solution and post your code through Disqus
Previous: Write a JavaScript program to get a boolean determining if the passed value is an object or not.
Next: Write a JavaScript program that will return true if the specified value is null, false otherwise.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
- Weekly Trends
- Python Interview Questions and Answers: Comprehensive Guide
- Scala Exercises, Practice, Solution
- Kotlin Exercises practice with solution
- MongoDB Exercises, Practice, Solution
- SQL Exercises, Practice, Solution - JOINS
- Java Basic Programming Exercises
- SQL Subqueries
- Adventureworks Database Exercises
- C# Sharp Basic Exercises
- SQL COUNT() with distinct
- JavaScript String Exercises
- JavaScript HTML Form Validation
- Java Collection Exercises
- SQL COUNT() function
- SQL Inner Join