JavaScript对象行为

Question

I do not get stumped often but I am just at a loss of words right now.

Using Chrome 37.0.2062.120 m

Can someone explain to me why my console.log(); is reporting these results?

JS code

var some_obj = {min:1};

var another_obj = {};

console.log(some_obj);

another_obj['sometarget'] = some_obj; // <- What is this sorcery?!?!?
another_obj['sometarget']['required'] = true;

console.log(some_obj);

console.log() output

Object {min: 1}
Object {min: 1, required: true}

JSFIDDLE

http://jsfiddle.net/qrnaw7j2/1/

Answer 1

Objects in javascript are shared via reference.

So some_obj and another_obj['sometarget'] point to the same place in memory.

When you set ['required'] = true; in any of them, they will both get updated.