javascript merge two arrays without duplicates code example

Example 1: 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 2: js merge 2 lists

var array1 = ["Vijendra", "Singh"];
var array2 = ["Singh", "Shakya"];

console.log(array1.concat(array2));
// output: ["Vijendra", "Singh", "Singh", "Shakya"]

Example 3: merge array no duiplicates js

let array1 = ['a','b','c'];
let array2 = ['c','c','d','e'];
let array3 = array1.concat(array2);
array3 = [...new Set([...array1,...array2])]; // O(n)

Example 4: compare two arrays and make sure there are no duplicates js

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