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:
html
<!DOCTYPE html><html> <head> <title> JavaScript includes() Method </title></head> <body> <h1>GeeksforGeeks</h1> <p id="geeks"></p> <!-- Script to check array include object or not --> <script> var obj = {"geeks1":10, "geeks2":12} var gfg = ["geeks1", "geeks2", obj]; /* Use JavaScript includes() method */ var num = gfg.includes(obj, 0); document.getElementById("geeks").innerHTML = num; </script></body> </html> |
Output:
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:
html
<!DOCTYPE html><html> <head> <title> JavaScript includes() Method </title></head> <body> <h1>GeeksforGeeks</h1> <!-- Script to check array include object or not --> <script> /* Declare an array */ var arr = ["geeks1", "geeks2", "geeks3", {1:"geeks4", 2:"geeks5"}]; var boolVar = arr.some( value => { return typeof value == "object" } ); document.write(boolVar); </script></body> </html> |
Output:
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:
html
<!DOCTYPE html><html> <head> <title> JavaScript includes() Method </title></head> <body> <h1>GeeksforGeeks</h1> <p id="geeks"></p> <!-- Script to check array include object or not --> <script> var obj = {"geeks1":10, "geeks2":12} var arr = ["geeks1", "geeks2", "geeks3", obj]; if(arr.filter(value=> value==obj).length > 0) document.write("true"); else document.write("false"); </script></body> </html> |
Output:
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
<!DOCTYPE html><html> <head> <title> JavaScript includes() Method </title></head> <body> <h1>GeeksforGeeks</h1> <!-- Script to check array include object or not --> <script> /* Declare an array */ var arr = ["geeks1", "geeks2", "geeks3", {"geeks1":10, "geeks2":12}]; var num = arr.findIndex( value => { return typeof value == "object" } ); document.write("Object found at position: " + num); </script></body> </html> |
Output:
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.
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