What is Destructuring Assignment? #
- It is a JS expression that allows you to unpack properties from arrays or objects into individual variables.
const user = {
name : `huemang`,
age : 17,
email : 's22043@gsm.hs.kr'
}
const { name , age , email, address} = user
console.log(name);
// humang
console.log(age);
// 17
console.log(email);
// s22043@gsm.hs.kr
console.log(address);
// undefined
- Arrays can also use destructuring assignment.
- If you want to extract only the third value, you can append a comma after the variable you want to extract the value into.
const fruits = ['apple' , 'banana' , 'Cherry']
const =[, , fruit] = fruits
console.log(fruit);
// Cherry
- If you assign a default value to a variable, that value will be used instead when the destructured value is
undefined.
let a, b;
[a=5, b=7] = [1];
console.log(a); // 1
console.log(b); // 7