Spread operator

Spread operator to the opposite job of Rest parameter.

Below all examples combined together, please check one by one. So that you can understand it easily.

// Normal way - will not work
let arr = [7, 5, 4];
alert( Math.max(arr) ); // NaN


//Could work with spread operator
let arr = [7, 5, 4];
alert( Math.max(...arr) ); // 7 (spread turns array into a list of arguments)


//Multiple iterables array
let arr1 = [1, -2, 6, 5];
let arr2 = [8, 9, -8, 7];

alert( Math.max(...arr1, ...arr2) ); // 9



//Combined
let arr1 = [1, -2, 6, 5];
let arr2 = [8, 9, -8, 7];

alert( Math.max(3, ...arr1, 2, ...arr2, 52, 56) ); // 56



//Merging array is easy
let arr = [3, 5, 1, 4, 6, 8];
let arr2 = [8, 9, 15, 2, 1, 7, 3];

let merged = [0, ...arr, 2, ...arr2];

alert(merged); // 0,3,5,1,4,6,8,2,8,9,15,2,1,7,3


// String into array of characters
let str = "Hello";

alert( [...str] ); // H,e,l,l,o