How to destructure an object to an already defined variable

Oct 28, 2023

Learn how to destructure an object into already declared variables in JavaScript using the parentheses assignment syntax, with a leading semicolon for safety.

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I had the need to assign the result of a function call to a variable already defined. The function returned an object:

function test() {
	return {
		one: 1,
		two: 2
	}
}

I thought I’ll just use object destructing, like this:

const { one, two } = test()

But I had two already defined in my code (because of scoping issues) and I couldn’t redeclare it:

let two

//...

const { one, two } = test() //ERROR

Simple way would be to have

const result = test()

two = result.two
const { one } = result

Or, I could also declare one as let and use this syntax with parentheses (adding ; before them to prevent JS to freak out because I don’t use semicolons, any line starting with ( must start with a semicolon, simple rule)

let one, two

;({ one, two } = test())

Tagged: JavaScript · All topics

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