为什么这给我一个错误？

Question

var nop = {}; 
var f = {}; 
[nop.foo] = (f.foo || undefined);

Note f.foo is not present.

Returns the following error:

Uncaught TypeError: Cannot read property 'Symbol(Symbol.iterator)' of undefined

Why?

Answer 1

It seems the reason is your destructuring [nope.foo] is not matching to (whatEver) so you'd better change it so:

 var nop = {}; var f = {}; [nop.foo] = [(f.foo || 23)]; console.log(nop)