How to add an array of values to a Set

Question

The old school way of adding all values of an array into the Set is:

// for the sake of this example imagine this set was created somewhere else 
// and I ca         


        

Answer 1

create a new Set:

    //Existing Set
    let mySet = new Set([1,2,3,4,5]);
    //Existing Array
    let array = [6,7,8,9,0];
        
    mySet = new Set(array.concat([...mySet]));
    console.log([...mySet]);
    
    //or single line
    console.log([...new Set([6,7,8,9,0].concat([...new Set([1,2,3,4,5])]))]);