Spread Operator & Rest Operator

Spread Operator

• we spread the original array or object without changing it

    // example 1 : object
    const animal = {
        status: 'healthy'
    }
  
    const dog = {
        ...animal,
        bark: true
    }
  
    console.log(animal) // {status: 'healthy'}
    console.log (dog) // {status: 'healthy', bark: true}
  
    // example 2 : array
    const animals = ['dog', 'cat']
    const moreAnimals = [...animals, 'bird'];
    const useMoreThanOneSpread = [...animals, 'bird', ...animals];
  
    console.log(animals) // ['dog', 'cat']
    console.log(moreAnimals) // ['dog', 'cat', 'bird']
    console.log(useMoreThanOneSpread ) // ['dog', 'cat', 'bird', 'dog', 'cat',]
  

Rest Operator

• Use it with array, object, and parameter

    // example 1 : object
    const dog = {
        status: 'healthy',
        bark: true,
        attribute: 'cute'
    }
  
    const {status, ...rest} = dog;
    console.log(status) // healthy
    console.log(rest) // {bark: true, attribute: 'cute'}
  
    // example 2 : array
    const numbers = [0, 1, 2, 3, 4, 5];
    const [one, ...rest] = numbers;
  
    console.log(one); // 0
    console.log(rest); // [1, 2, 3, 4, 5]
  
    // example 3 : parameter
    function returnRest(...rest) {
      return rest;
    }
  
    const result1 = returnRest(1, 2, 3, 4, 5);
    console.log(result1); // [1, 2, 3, 4, 5]