get rid of duplicates typescript code example
Example 1: js delete duplicates from array
const names = ['John', 'Paul', 'George', 'Ringo', 'John'];
let unique = [...new Set(names)];
console.log(unique); // 'John', 'Paul', 'George', 'Ringo'
Example 2: javascript remove uniques from array
function getNotUnique(array) {
var map = new Map();
array.forEach(a => map.set(a, (map.get(a) || 0) + 1));
return array.filter(a => map.get(a) > 1);
}
console.log(getNotUnique([1, 2, 2, 4, 4])); //[2, 2, 4, 4]
console.log(getNotUnique([1, 2, 3] )); //[]