ES6 SPREAD Operator

Spread syntax allows an iterable such as an array expression or string to be expanded in places where zero or more arguments (for function calls) or elements (for array literals) are expected, or an object expression to be expanded in places where zero or more key-value pairs (for object literals) are expected.

1. Copying an array

   let fruits = ['Apple','Orange','Banana']; let newFruitArray = [...fruits]; console.log(copiedList); // ['Apple','Orange','Banana']

2. Concatenating arrays

   let arr1 = ['A', 'B', 'C']; let arr2 = ['X', 'Y', 'Z']; let result = [...arr1, ...arr2]; console.log(result); // ['A', 'B', 'C', 'X', 'Y', 'Z']

3. Spreading elements together with an individual element

   let fruits = ['Apple','Orange','Banana']; let newFruits = ['Cherry', ...names]; console.log(newFruits); // ['Cherry', 'Apple','Orange','Banana']

4. Spreading elements on function calls

   let fruits = ['Apple','Orange','Banana']; var getFruits = (f1, f2, f3) => {console.log(Fruits: {f2} and ${f3}); }; getFruits(...fruits); // Fruits: Apple, Orange and Banana

5. Spread syntax for object literals

   var obj1 = { id: 101, name: 'Jhon Doe' } var obj2 = { age: 25, country: 'USA'} const employee = { ...obj1, ...obj2 } console.log(employee); //{ "id": 101, "name": "Jhon Doe", "age": 25, "country": "USA" }