mheiber/bm.js

## bm.js
const main = () => {
    const x = 2
    const y = 3

    ;[1, 2, 3].forEach(v => {
        console.log(v, y)
    })

    console.log(x, y)
}

main()

## clos.md

      
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              clos.md
            
          
    I think V8 optimizes away x in the forEach callback since it is not used there. See the Closures listed in the debugger.

And if you don't access y, it goes away, too.
I would be surprised if this mattered either way, since the function's stack frame is short-lived.
	const main = () => {
	const x = 2
	const y = 3

	;[1, 2, 3].forEach(v => {
	console.log(v, y)
	})

	console.log(x, y)
	}

	main()