How to check if the value is a number in javascript

In this tutorial, we are going to learn about how to check if a given is a number or not in JavaScript with the help of examples.

Using Number.isInteger() method

In JavaScript, we can use the Number.isInteger() method to check whether a given value is a number or not.

The Number.isInteger() method returns true if a given value is a number, otherwise it returns false.

Here is an example:

function isNumeric(value){
   return Number.isInteger(value);
}

isNumeric(1222); // true

isNumeric('1222'); // false

isNumeric('booo'); // false

If the given value is Infinity or not a number it returns false.

isNumeric(Infinity) //  false

isNumeric(-Infinity) //  false

isNumeric(0) // true

Similarly, we can also use the isNan() function in JavaScript.

isNan(3); // false
isNan(4); // false

isNan('hi'); // true

The isNan() function returns false if a value is a number; otherwise true.