Remove duplicate values in an array

JavaScript

const removeDuplicate = (arr) => arr.filter((i) => arr.indexOf(i) === arr.lastIndexOf(i))

TypeScript

const removeDuplicate = <T,_>(arr: T[]): T[] => arr.filter((i) => arr.indexOf(i) === arr.lastIndexOf(i))

Example

removeDuplicate(['h', 'e', 'l', 'l', 'o', 'w', 'o', 'r', 'l', 'd']) //  ['h', 'e', 'w', 'r', 'd']