freeCodeCamp/guide/english/javascript/standard-objects/object/object-is/index.md

title
Object Is

Object Is

Description

The object.is() method is used to determine if two values are the same value. This method was introduced in ES6.

Syntax

Object.is(val1, val2)

Parameters

val1 - first value to compare

val2 - second value to compare

Return value

A Boolean indicating whether the two arguments have the same value

Description

Object.is() compares two values for sameness, returning true if both values meet one of the following conditions:

• undefined
• null
• Both true or both false
• String of the same length and same characters
• Same object
• Both numbers and:
  • Both +0 or both -0
  • Both NaN
  • or both a number that is not zero and not NaN

Examples

Object.is('string', 'string'); // true
Object.is(undefined, undefined); // true
Object.is(null, null); // true

Object.is('string, 'word'); // false
Object.is(true, false); // false
Object.is([], []); //false  

var obj = {name: Jane};
Object.is(obj, obj); // true

Object.is(NaN, NaN); // true

Object.is(+0, -0); // false
Object.is(-0, -0); // true

More Information:

Object.is() MDN Web Docs
Strict equality operator ===