Why square brackets allow use of variable value as object key?

user_8381957 0
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code:

const x = 6;
const ob = {x: [6.1, 6.5]} 
console.log(ob) // {x: [6.1, 6.5]}

const y = 6;
const ob = {[y] : [6.1, 6.5]};
console.log(ob) // {6: [6.1, 6.5]}

Why square brackets allow use the value of the variable as object key, is this related to destructuring??

javascript
2 Answers

The square brackets allow for computed property keys. In other words, the value of the variable inside of the square brackets is processed before the value is accessed.

user_80749490

Its called Computed Property Names, its implemented using bracket notation(square brackets) []

Example: { [variableName] : someValue }

For ES5, try something like this

var yourObject = {};

yourObject[yourKey] = "yourValue";

console.log(yourObject );

Example:

var person = {};
var key = "name";

person[key] /* this is same as person.name */ = "John";

console.log(person); // should print  Object { name="John"}
user_96652100
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