Check if a variable exists in JavaScript

Subash Chandran 24th September 2020 Leave a Comment

Find out how to find out if a variable exists in JavaScript.

 var num = 20;
 if(num !== undefined && num !== null) {
     document.write("Variable 'num' exists");
 }

Related

See also Find the largest number contained in a JavaScript array

Solutions

Check if a File exists in C#, Check if a file exists in Java, Check if MongoDB database exists?, How can I check if a JavaScript variable is function type?, How do I check if a Python variable exists?, How to check if a file exists or not in Java?, How to check if a key exists in a Python dictionary?, How to check if a MySQL database exists?, How to check if a python module exists without importing it?, how to check if a variable is an array in javascript, How to check if a variable is an integer in JavaScript?, How to check if a variable is boolean in JavaScript?, How to check if a variable is NaN in JavaScript?, How to check if an alert exists using WebDriver?, How to check if an item exists in a C# array?

Leave a Reply Cancel reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.