This article will show you how to Check if an Array Contains a Certain Item in JavaScript. There are several approaches to check if an array contains a certain item in JavaScript, each with a description and complete code example are given below:
1. Using Array.includes() Method
Using the includes()
method to check if an array contains a specific item.
const array = ['Apple', 'Banana', 'Orange']; const itemToCheck = 'Banana'; const containsItem = array.includes(itemToCheck); // Output: true console.log(containsItem);
2. Using Array.indexOf() Method
Using the indexOf()
method to check if an array contains a specific item and getting its index.
const array = ['Apple', 'Banana', 'Orange']; const itemToCheck = 'Banana'; const containsItem = array.indexOf(itemToCheck) !== -1; // Output: true console.log(containsItem);
3. Using Array.includes() in a Function
Creating a function that uses includes()
to check if an item exists in an array.
function containsItem(array, item) { return array.includes(item); } const fruits = ['Apple', 'Banana', 'Orange']; const itemToCheck = 'Banana'; const result = containsItem(fruits, itemToCheck); // Output: true console.log(result);
4. Using Array.some() Method
Using the some()
method to check if any element in the array satisfies a condition.
const array = ['Apple', 'Banana', 'Orange']; const itemToCheck = 'Banana'; const containsItem = array.some(item => item === itemToCheck); // Output: true console.log(containsItem);
5. Using Array.find() Method
Using the find()
method to find the first element in the array that satisfies a condition.
const array = ['Apple', 'Banana', 'Orange']; const itemToCheck = 'Banana'; const containsItem = array.find(item => item === itemToCheck) !== undefined; // Output: true console.log(containsItem);
6. Using a for Loop
Using a traditional for
loop to iterate over the array and check if it contains a specific item.
const array = ['Apple', 'Banana', 'Orange']; const itemToCheck = 'Banana'; let containsItem = false; for (let i = 0; i < array.length; i++) { if (array[i] === itemToCheck) { containsItem = true; break; } } // Output: true console.log(containsItem);
7. Using Array.filter() Method
Using the filter()
method to create a new array with elements that satisfy a condition.
const array = ['Apple', 'Banana', 'Orange']; const itemToCheck = 'Banana'; const filteredArray = array.filter(item => item === itemToCheck); const containsItem = filteredArray.length > 0; // Output: true console.log(containsItem);