YogeshChauhan.com

The difference between isFinite() method and isFinite() function in JavaScript

July 8, 2020

JavaScript isFinite() Function

The isFinite() function determines whether a number is a finite, legal number. 

If  needed, the parameter is first converted to a number.

This function returns false if the value is +infinity, -infinity, or NaN (Not-a-Number), otherwise it returns true.

Syntax


isFinite(testValue)

where testValue = The value to be tested for finiteness.

Examples


console.log(isFinite(1)) //true
console.log(isFinite(-1.99)) //true
console.log(isFinite(4-2)) //true
console.log(isFinite(0)) //true
console.log(isFinite("1")) //true
console.log(isFinite("string")) //false
console.log(isFinite("2020/5/5")) //false

JavaScript isFinite() Method

Checks whether a value is a finite number.

This method returns true if the value is of the type Number, and equates to a finite number. Otherwise it returns false.

Examples


Number.isFinite(1) //true
Number.isFinite(-1.1) //true
Number.isFinite(4-2) //true
Number.isFinite(0) //true
Number.isFinite('1') //false
Number.isFinite('String') //false
Number.isFinite('2020/5/5') //false
Number.isFinite(Infinity) //false
Number.isFinite(-Infinity) //false
Number.isFinite(0 / 0) //false

You must have noticed the difference.

If not, let me show here separately.


//function
console.log(isFinite("1")) //true

//method
Number.isFinite('1') //false

//in case you're thinking about quotes, they don't matter. You can use either one.

Almost everything is the same about the method and function, except one thing.

The global isFinite() function converts the tested value to a Number, then tests it.

Number.isFinite() does not convert the values to a Number, and will not return true for any value that is not of the type Number.

dreamhost

Most Read

#1 How to check if radio button is checked or not using JavaScript? #2 Solution to “TypeError: ‘x’ is not iterable” in Angular 9 #3 How to uninstall Cocoapods from the Mac OS? #4 How to Use SQL MAX() Function with Dates? #5 How to add Read More Read Less Button using JavaScript? #6 PHP Login System using PDO Part 1: Create User Registration Page

Recently Posted

Apr 7 Solution for “Yarn build: Failed because of a stylelint error” Apr 7 Make sure your links have descriptive text Apr 7 How to add Laravel to WordPress using Sage theme (and install Tailwind CSS)? Apr 2 How to create a sidebar using pure CSS? Apr 1 How to switch dark and light themes using pure CSS? Apr 1 How to calculate elapsed time in JavaScript?

You might also like these

CSS backface-visibility PropertyCSSGeneral concepts in DrupalDrupalHow to create a simple text and image slider using CSS and JavaScript?CSSHow to avoid element shift on border change while hovering in CSS?CSSFive common features of Angular template syntax (with examples)Angularapply_filters function in WordPressWordPress