includes() / indexOf()
method
ES6
includes() checks if an element exists (returns boolean); indexOf() returns its position.
Syntax
array.includes(value) array.indexOf(value)
Example
javascript
const fruits = ['apple', 'banana', 'cherry'];
console.log(fruits.includes('banana')); // true
console.log(fruits.includes('grape')); // false
console.log(fruits.indexOf('cherry')); // 2
console.log(fruits.indexOf('grape')); // -1
// Practical check
if (fruits.includes('apple')) {
console.log('We have apples!');
}