how remove duplicates in an array code example

Example 1: remove duplicates from array javascript

arr.filter((v,i,a)=>a.findIndex(t=>(t.place === v.place && t.name===v.name))===i)

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] )); //[]