why do we need array destructuring in javascript code example

Example 1: destructure array javascript

var [first, second, ...rest] = ["Mercury", "Earth", ...planets, "Saturn"];

Example 2: javascript destructuring

const classDetails = {
  strength: 78,
  benches: 39,
  blackBoard:1
}

const {strength:classStrength, benches:classBenches,blackBoard:classBlackBoard} = classDetails;

console.log(classStrength); // Outputs 78
console.log(classBenches); // Outputs 39
console.log(classBlackBoard); // Outputs 1