js spread arguments code example

Example 1: array spread operator in javascript

let arr1 = ['A', 'B', 'C'];

let arr2 = ['X', 'Y', 'Z'];

let result = [...arr1, ...arr2];

console.log(result); // ['A', 'B', 'C', 'X', 'Y', 'Z']
// spread elements of the array instead of taking the array as a whole

Example 2: spread operator javascript

const parts = ['shoulders', 'knees']; 
const lyrics = ['head', ...parts, 'and', 'toes']; 
//  ["head", "shoulders", "knees", "and", "toes"]

Example 3: spread and rest operator javascript

var myName = ["Marina" , "Magdy" , "Shafiq"] ;const [firstName , ...familyName] = myName ;console.log(firstName); // Marina ;console.log(familyName); // [ "Magdy" , "Shafiq"] ;

Example 4: js spread parameters

// seperate each element of array using ...
let list = ['a','b','c'];
let copy = [...list, 'd', 'e']; // ['a', 'b', 'c', 'd', 'e']
//use for infinite parameters to a function
function toDoList(...todos) {
  //todos is an array, so it has map function
  document.write(
    `<ul>${todos.map((todo) => `<li>${todo}</li>`).join("")}</ul>`
  );
}
toDoList("wake up", "eat breakfast", ...list); //ul containing: wake up eat breakfast a b c

Example 5: spread operator es6

[...fruits]