use include to delete duplicate array code example

Example 1: remove duplicates from array

let chars = ['A', 'B', 'A', 'C', 'B'];
let uniqueChars = [...new Set(chars)];

console.log(uniqueChars);

output:
[ 'A', 'B', 'C' ]

Example 2: remove duplicates array.filter

// removeDuplicates ES6
const uniqueArray = oldArray.filter((item, index, self) => self.indexOf(item) === index);