How to check if an array includes an object in JavaScript ?

There are various methods to check an array includes an object or not.

Using includes() Method: If array contains an object/element can be determined by using includes() method. This method returns true if the array contains the object/element else return false.

Syntax:

array.includes( element/object, startingPosition )

Example:

Javascript

var obj = {"geeks1":10, "geeks2":12}
var gfg = ["geeks1", "geeks2", obj];

/* Use JavaScript includes() method */
var num = gfg.includes(obj, 0);

console.log(num)

Output:

true

Using some() Method: The some() method uses the function for its evaluation and it executes the function once for each element present in the array. If it finds the object/element in the array then it returns true and stop the execution for remaining elements otherwise return false.

Syntax:

array.some( function(currValue, arrIndex, arrObj), this )

Example:

Javascript

var arr = ["geeks1", "geeks2", "geeks3",
            {1:"geeks4", 2:"geeks5"}];

var boolVar = arr.some(
    value => { return typeof value == "object" } );

console.log(boolVar);

Output:

true

Using filter() Method: The filter() method creates the array of all those elements/objects that passes the checking condition.

Syntax:

array.filter( function(currValue, arrIndex, arrObj), this )

Example:

Javascript

var obj = {"geeks1":10, "geeks2":12}
var arr = ["geeks1", "geeks2", "geeks3", obj];

if(arr.filter(value=> value==obj).length > 0)
    console.log("true");
else
    console.log("false");

Output:

true

Using findIndex() Method: The findIndex() method returns the position of searched object/element if it present in the array and stop the execution for rest elements. If the element/object not found then return -1.

Syntax:

array.findIndex( function(currValue, arrIndex, arrObj), this )

Example:

html

var arr = ["geeks1", "geeks2", "geeks3",
        {"geeks1":10, "geeks2":12}];

var num = arr.findIndex(
    value => { return typeof value == "object" } );

console.log("Object found at position: " + num);

Output:

Object found at position: 3

JavaScript is best known for web page development but it is also used in a variety of non-browser environments. You can learn JavaScript from the ground up by following this JavaScript Tutorial and JavaScript Examples.