js delete duplicates from array

1const names = ['John', 'Paul', 'George', 'Ringo', 'John'];
2
3let unique = [...new Set(names)];
4console.log(unique); // 'John', 'Paul', 'George', 'Ringo'

1const names = ['John', 'Paul', 'George', 'Ringo', 'John'];
2
3let x = (names) => names.filter((v,i) => names.indexOf(v) === i)
4x(names); // 'John', 'Paul', 'George', 'Ringo'

1const names = ['John', 'Paul', 'George', 'Ringo', 'John'];
2
3function removeDups(names) {
4  let unique = {};
5  names.forEach(function(i) {
6    if(!unique[i]) {
7      unique[i] = true;
8    }
9  });
10  return Object.keys(unique);
11}
12
13removeDups(names); // // 'John', 'Paul', 'George', 'Ringo'

1let a = [10,20,30,10,30];
2let b = a.filter((item,index) => a.indexOf(item) === index);
3console.log(b); 

1function toUniqueArray(a){
2    var newArr = [];
3    for (var i = 0; i < a.length; i++) {
4        if (newArr.indexOf(a[i]) === -1) {
5            newArr.push(a[i]);
6        }
7    }
8  return newArr;
9}
10var colors = ["red","red","green","green","green"];
11var colorsUnique=toUniqueArray(colors); // ["red","green"]

1//ES6
2let uniqueArray = [...new Set(arrayWithDuplicates)];
3
4//Alternative
5function removeArrayDuplicates(arrayWithDuplicates) {
6    let seen = {};
7    let uniqueArray = [];
8    let len = arrayWithDuplicates.length;
9    let j = 0;
10    for(let i = 0; i < len; i++) {
11         let item = arrayWithDuplicates[i];
12         if(seen[item] !== 1) {
13               seen[item] = 1;
14               uniqueArray[j++] = item;
15         }
16    }
17    return uniqueArray;
18}