// example of pass array by value 
let arr = [ 1 , 2 , 3 ];

// new Array => constructor take args & make array using it
// ...arr => just extract all array elements in this place
let arr_copy = new Array( ...arr );  // pass by value

arr_copy[0] = 99; // proof :)

console.log( arr );      // output => [ 1  , 2 , 3 ]
console.log( arr_copy ); // output => [ 99 , 2 , 3 ]