javascript compare two arrays and remove duplicates 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 duplicate in two arrays

array1 = array1.filter(function(val) {
  return array2.indexOf(val) == -1;
});
// Or, with the availability of ES6:

array1 = array1.filter(val => !array2.includes(val));

Example 3: javascript to remove duplicates from an array

uniqueArray = a.filter(function(item, pos) {
    return a.indexOf(item) == pos; 
})

Example 4: javascript remove duplicates from array

unique = [...new Set(arr)];   // where arr contains duplicate elements

Example 5: remove duplicates from array javascript

function onlyUnique(value, index, self) {
  return self.indexOf(value) === index;
}

// usage example:
var a = ['a', 1, 'a', 2, '1'];
var unique = a.filter(onlyUnique);

console.log(unique); // ['a', 1, 2, '1']