w = {c: true}
w =
a: 4
b: true
console.log w
I expect the result w to be {a: 4, b: true, c: true}, but I get {a: 4, b: true}.
How can I do multiple assignments to object properties without loosing already set properties?
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1The answers to this question might prove useful, as what you're doing is merging properties in to the initial object.pjmorse– pjmorse2014-09-17 14:35:40 +00:00Commented Sep 17, 2014 at 14:35
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3 Answers
CoffeeScript: assigning multiple properties to an initialised object has been the best answer so far.
But if you only want to add a few properties to an object you can just do:
w = {c: true}
w.a = 4
w['b'] = true # alternative notation
Also, this question is more about JavaScript than CoffeeScript.
1 Comment
ronnydw
That's obviuous I know ... but not very pretty, I am looking for a short notation, in real life w is an object with a long name and I have many properties to add.
I don't think it can be done directly. I believe, you need to iterate:
w = {c: true}
temp =
a: 4
b: true
w[k] = v for k,v of temp
console.log w
3 Comments
ronnydw
hmm... this does the assigment of each property twice
Jakub Fedyczak
True, but solution from @Yuri does it same way - look at the transpiled code.
Jakub Fedyczak
Most efficient way seems to be from @Tomasz Zieliński - not very pretty though.
w = {c: true}
w[i] = v for i,v of {
a: 4
b: true
}
console.log w
