Array Methods - indexOf, lastIndexOf, includes
Let's explore methods used to find a specific element in an array.
indexOf
Finds a specific element in an array and returns its index. If the element is not found, -1 is returned.
Example of indexOf() Method
const fruits = ['Apple', 'Banana', 'Cherry', 'Apple'];
const index = fruits.indexOf('Apple');
console.log(index); // 0
In the example above, "Apple" is at index 0 in the array, so 0 is printed.
lastIndexOf
Finds the last occurrence of a specific element in an array and returns its index. If the element is not found, -1 is returned.
Example of lastIndexOf() Method
const fruits = ['Apple', 'Banana', 'Cherry', 'Apple'];
const lastIndex = fruits.lastIndexOf('Apple');
console.log(lastIndex); // 3
"Apple" last appears at index 3 in the array, so 3 is printed.
includes
Checks whether a specific element exists in an array. Returns true if it exists, otherwise false.
Example of includes() Method
const fruits = ['Apple', 'Banana', 'Cherry'];
const hasApple = fruits.includes('Apple');
console.log(hasApple); // true
In the example above, since the array contains "Apple", true is printed.
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