"js spread parameters" Code Answer's

spread operator in javascript

By peachmangopie on Dec 03, 2020

// spread operators can be used for arrays or objects

// cloning to prevent mutation.
let numList = [1,2,3];
let numListClone = [...numList]; // [1, 2, 3]

// spread operator for destructuring.
let animal = {
  name: 'dog',
  color: 'brown',
  age: 7
};
let { age, ...otherProperties } = animal; 

// spread operator as rest operator
function sum(x, y, ...rest) {}

// spread operator for merging arrays or objects
let numLists = [...numList1, ...numList2];
let animalWithBreed = {
  ...animal,
  breed: '',
}

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array spread operator in javascript

By Alert Albatross on May 25, 2020

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

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spread operator javascript

By Cherry berry on Dec 16, 2020

obj = {first_name : "Marty",
    lovers: ["Jennifer Parker","Baines McFly"]
      };
let objClone = { ...obj }; // pass all key:value pairs from an object 

console.log(objClone)
// { first_name: "Marty", lovers: ["Jennifer Parker", "Baines McFly"] }

Source: developer.mozilla.org

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js spread parameters

By Google on Jan 25, 2021

// 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

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