YDKJS: this and object prototypes - Ch3 - Contents Section Question

1

Here’s the link to that section.

In the last code snippet in this section:

var myObject = { };
myObject[true] = "foo";
myObject[3] = "bar";
myObject[myObject] = "baz";

myObject["true"];				// "foo"
myObject["3"];					// "bar"
myObject["[object Object]"];	// "baz"

Can someone explain to me how this line myObject["[object Object]"]; value equals baz?

2

Bracket notation only accepts string values. When you do

myObject[myObject] = 'baz'

the myObject in the brackets is coerced to a string, which happen to be '[object Object]'. That’s why you got the same 'baz' when you do myObject['[object Object]'].

1 Like
3

Why it didn’t coerce it to "myObject"?

4

That’s how the spec for the language defined coercing objects to strings by default. You can define your own way of coercing objects to strings.

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5

I see. Thank you. :slight_smile: