Answers for "search array for non duplicates javascript"

javascript create array with repeated values

Array(5).fill(2)
//=> [2, 2, 2, 2, 2]

how to get duplicate values from array in javascript

let a = [1, 2, 3, 4, 2, 2, 4, 1, 5, 6]
let b = [...new Set(a.sort().filter((o, i) => o !== undefined && a[i + 1] !== undefined && o === a[i + 1]))]

// b is now [1, 2, 4]