It is possible to do:
let a = 1,
b = 3,
c = 9;
Is it also possible to do:
obj.a = 1,
b = 2,
c = 3;
This is still very readable, but a lot less typing, then writing obj a lot of times.
5 Answers
If the variables are already defined, you can use shorthand property names to define the object in one go, without any repetition:
const obj = { a, b, c };
answered Apr 7, 2019 at 3:44
CertainPerformance
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Comments
You can assign the defined variables using shorthand property names
let a = 1,
b = 3,
c = 9;
let obj = {a,b,c}
console.log(obj)4 Comments
Muhammad Umer
this is the best so far. although double memory usage but very easy to follow
Jaromanda X
double memory usage huh?
Code Maniac
@MuhammadUmer in most cases memory useage will not be an issue as JS uses grabage collector
Muhammad Umer
true. this what i'm doing right now too. so it's good to see it's being recommended. only problem i see is i'm declaring/assigning 2x variables for same amount of data. but not a big or even medium problem.
If there exists a relation between the property names and the values then one can write a compact object definition using map. Otherwise one can just initialize the object with names and values.
// function
var obj = {};
['a', 'b', 'c'].map((x, i) => (obj[x] = i));
console.log(obj);
// no function
var obj1 = {a: 1, b: 2, c: 4};
console.log(obj1);
Comments
If the variables are not already assigned, you could use Object.assign:
const obj = Object.assign({}, { a: 1, b: 2, c: 3 });
console.log(obj);Otherwise, use ES6 shorthand property notation:
const [a, b, c] = [1, 2, 3];
const obj = { a, b, c };
console.log(obj);
Comments
You can do this (if object is re-assignable ex: let NOT const ):
obj = {...obj, a : 1,
b : 2,
c: 3,
}
Thank you :)
Object.assign(obj, { a: 1, b: 2, c: 3 });would do it in 1 line, but just assigning 3 times in a row is not a bad thing