public/subjects/index-of

Index Of

Instructions

Create 3 functions which accept an array to be searched, and a value to be matched.

• indexOf: which returns the index of the first occurrence. It also accepts an optional index from where the search should begin. If the value was not found, -1 is returned.
• lastIndexOf: which works just like your indexOf function, but returns the index of the last occurrence.
• includes: which returns true if the value was found in the array, and false otherwise.

Of course you must not use any of Array.indexOf(), Array.lastIndexOf() or Array.includes().

Notions

• Array.indexOf
• Array.lastIndexOf
• Array.includes

Code provided

The provided code will be added to your solution, and does not need to be submitted.

Array.prototype.indexOf = undefined
Array.prototype.lastIndexOf = undefined
Array.prototype.includes = undefined