JavaScript Object is() Method

JavaScript Object.is() method is used to compare if two values are the same value.

Object.is() returns true if the values are the same, and false otherwise. It differs from the strict equality operator === in the handling of NaN and positive/negative zero.

Syntax:

Object.is(value1, value2)

Parameters:

Object.is() Method takes two parameters:

• value1: It is the first value to be compared. 
• value2: It is the second value to be compared.

Return Value:

Object.is() returns a boolean indicating whether the two arguments are the same or not. 

JavaScript Object is() Method Examples

Example: In this example, Object.is() returns true for the first comparison because both values are 5, but false for the second comparison because 5 and '5' are of different types. It returns true for NaN comparison because NaN is considered the same value as itself, and false for 0 and -0 comparison because they are considered different values.

Javascript

console.log(Object.is(5, 5)); // true
console.log(Object.is(5, '5')); // false
console.log(Object.is(NaN, NaN)); // true
console.log(Object.is(0, -0)); // false

Output

true
false
true
false

Exceptions

• The “==” and “===” operator treats the number values “+0” and “-0” as equal but the object.is() method treats them differently.
• The Object.is() method does not coerce values before comparison even if they are of different data types.

Two values can be the same if they hold one of the following properties: 

• If both the values are undefined.
• If both the values are null.
• If both the values are true or false.
• If both the strings are of the same length with the same characters and in the same order.
• If both the values are numbers and both are “+0” or both are ‘-0’.
• If both the values are numbers and both are “NaN” or both non-zero and both not NaN and both have the same value. 

We have a complete list of Javascript Object methods, to check those please go through this JavaScript Object Complete Reference article.

Supported Browser:

• Google Chrome30 and above
• Edge 12 and above
• Firefox 22 and above
• Opera 17 and above
• Safari 9 and above