object destructuring without var

Question

Why does object destructuring throw an error if there is no var keyword in front of it?

{a, b} = {a: 1, b: 2};

throws Sy

Answer 1

Here's another way:

let {} = {a, b} = objectReturningFunction()

Pros:

• No parenthesis needed
• No semicolons needed
• The extra assignment is a guaranteed no-op (given that no weird things are going on)

Cons:

• Looks a bit weird, although in my opinion no weirder than the !(){...}() IIFE.
• Might be confusing as to why it's there. It is guaranteed to throw people off on the first encounter, so I would advise against using it as a one-off.