Using a Set (ECMAScript 2015), it will be as simple as that:

const array1 = ["Vijendra", "Singh"];
const array2 = ["Singh", "Shakya"];
const array3 = Array.from(new Set(array1.concat(array2)));

Using a Set (ECMAScript 2015), it will be as simple as that:

const array1 = ["Vijendra", "Singh"];
const array2 = ["Singh", "Shakya"];
console.log(Array.from(new Set(array1.concat(array2))));