array destructuring default value code example

Example 1: destructuring arrays with rest operator

// Rest operator on Arrays;
// It's usually shown as ...rest
// but you can name this what you like
// Think of it as "get the ...rest of the array"
const [q, r, ...callThisAnythingYouWant] = [1, 2, 3, 4, 5, 6, 7, 8];

console.log(q, r); // 1 2
console.log(callThisAnythingYouWant); // [ 3, 4, 5, 6, 7, 8 ]

Example 2: javascript deconstruct object

const objA = {
 prop1: 'foo',
 prop2: {
   prop2a: 'bar',
   prop2b: 'baz',
 },
};

// Deconstruct nested props
const { prop1, prop2: { prop2a, prop2b } } = objA;

console.log(prop1);  // 'foo'
console.log(prop2a); // 'bar'
console.log(prop2b); // 'baz'

Example 3: object destructuring default value

let a, b;

[a=5, b=7] = [1];
console.log(a); // 1
console.log(b); // 7