Destructuring Objects
Like destructuring arrays, destructuring objects helps you and makes your code cleaner and better, but it’s different from destructuring arrays, here is how to do it:
- First, for the whole explanation we will need this object, I used a sponge bob analogy for the object ??, so take a look at it and analyze it a little bit:
let heightInCm = 4; const obj = { personName: 'spongeBob', personAge: 37, personAddress: '124 Conch Street, Bikini Bottom, Pacific Ocean', heightInCm: 10, personHobbies: [ 'Jellyfishing', 'Cooking Krabby Patties', 'Blowing Bubbles', 'Karate', ], home: { type: 'pineapple', location: 'bikini bottom', details: { rooms: 3, uniqueFeature: "it's underwater and shaped like a pineapple!", }, }, };
- now, let’s destruct two properties from the object:
const { personName, personAge } = obj; console.log(personName, personAge); // spongeBob 37
- as you saw, to destruct an object you have to use {curly braces}, then inside it, write variable names that are exactly the same as the property names we want to retrieve in the object.
*You can also make variable names different from the property names, just right the new variable name after a colon:
const { personName: name, personAge: age } = obj; console.log(name, age); // spongeBob 37
- as you can see, we changed personName to name & personAge to age.
*Default Values:
- we can also set default values, in case when we try to access a property that does not exist in the object, example:
const { DriversLicense = ['no'] } = obj; console.log(DriversLicense); // ['no'] // DriversLicense does not exist in obj, so the default value will be used.
* Mutating Variables while Destructuring Objects:
({ heightInCm } = obj); console.log(heightInCm); // 10
- in this example, if you look back you will find out that heightInCm = 4 outside the object, and we wanted to assign the value inside the object to the heightInCm outside, so we did it like a normal destructuring, BUT JavaScript expects a code block when starting with { } outside a function, so we wrap the statement in parentheses to make it valid.
*Nested object destructuring:
// firstway: Extracting the Entire Nested Object const { details } = obj.home; console.log(details); // { rooms: 3, uniqueFeature: "it's underwater and shaped like a pineapple" // second way: Extracting Specific Properties const { home: { details }} = obj; console.log(details); // {rooms: 3, uniqueFeature: "it's underwater and shaped like a pineapple" // third way const {details: { rooms, uniqueFeature }} = obj.home; console.log(rooms, uniqueFeature); // 3 "it's underwater and shaped like a pineapple!"
- Best for clarity: The first way can be better when you're working with larger objects and prefer to keep things clear by extracting a whole object first.
- Best for efficiency: The third way is often the best if you're only interested in specific properties from a deeply nested object. It's concise and avoids creating unnecessary variables.
*Thanks for reading, hope you understand everything, if you have any questions feel free to ask ?
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