Post Link : Check If Variable Is A Number In JavaScript
This tutorial explains how to check variable is a number in javascript. Lets see the below example, where we have used typeof operator and isNaN() function to verify the variable is number or not.
typeof – If variable is a number, it will returns a string named "number".
isNaN() – Stands for "is Not a Number", if variable is not a number, it return true, else return false.
Using typeof operator :
In this example, we have used typeof operator, and verifying the variable is number or not in javscript.
// In this variable we are storing number...
var num1 = 758;
// verifying by using typeof operator
if(typeof num1 == 'number'){
console.log(num1 + " is a number.");
}else{
console.log(num1 + " is not a number.");
}
Output :
"758 is a number."
Top comments (1)
Hey there skptricks!
I stumbled upon this while writing my own and wanted to point out something.
You cannot rely on
isNaN()
for checking if something is a number. You can use it to check if the input provided toisNaN()
will cause furtherNaN
values. If that makes sense.Using it the way you have,
true
andfalse
will result intrue is a number.
Here's a function I wrote to check if something is a number: codepen.io/grok/pen/LvOQbW?editors...