JavaScript indexOf() method in an Object Array Examples
Example 1: Basic Usage
In this example, the indexOf()
method returns -1 because the object { name: 'banana', color: 'yellow' }
is a different object instance than the one stored in the array.
let fruits = [
{ name: 'apple', color: 'red' },
{ name: 'banana', color: 'yellow' },
{ name: 'orange', color: 'orange' }
];
// Find the index of an object in the array
let index = fruits.indexOf({ name: 'banana', color: 'yellow' });
console.log(index); // Output: -1 (Not found)
Output
-1
Example 2: Index of Modified Object
In this case, the modified banana
object is added to the array, and then indexOf()
method returns the index where this modified object is located.
// Example Title: Finding Index of a Modified Object
// Array of objects representing fruits
let fruits = [
{ name: 'apple', color: 'red' },
{ name: 'banana', color: 'yellow' },
{ name: 'orange', color: 'orange' }
];
let banana = { name: 'banana', color: 'yellow' };
// Finding the index of an object after modifying it
fruits.push(banana); // Adding the modified object to the array
let index = fruits.indexOf(banana);
console.log(index); // Output: 3
Output
3
JavaScript indexOf() method in an Object Array
In JavaScript, indexOf() methods provide the first index at which the given element exists, and -1 in case it is not present in the array.
Syntax:
indexOf(element)
indexOf(element, start);
Parameters:
- element: the element to be searched in the input array
- start: the index from which the search has to begin. The default value is set to 0.
Return value:
JavaScript indexOf() method returns the value of the index at which the element is present, and -1 when the element doesn’t exist.