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:

<!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:

<!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:

<!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:

<!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 postion: " + num); 
    </script> 
</body> 
  
</html>                     

Output:

My Personal Notes

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