How does the String constructor function in Javascript return an Object without a key?

Question

When I do new String("hello") in my console I get the following result:

String {"hello", length: 5}

The first value in the String Object that was returned doesn't have a key.

Since objects are associative/hash arrays i.e. defined and created with keys and values how is the String constructor returning an object with a value without key?

Which browser? That's not what i get in Chrome. I get a char array with the proper length and the String prototype. — sjahan, Jul 30 '18 at 07:41
`length: 0` ? But still: what you see in the console is not always what the objects look like in js — Jonas Wilms, Jul 30 '18 at 07:42
@Vipinkumar Singh: String is an array of characters. That is what the console outputs you if you expand the output. — Lain, Jul 30 '18 at 07:46
@Vipinkumar Singh: Yes, you edited length from 0 to 5. Now it is equal. — Lain, Jul 30 '18 at 07:47
@VipinkumarSingh That's just Chrome displaying it. It's not a key/value pair where one of the pairs has no key. Don't read too much into the console output. — Reinstate Monica Cellio, Jul 30 '18 at 07:47
@Lain How does this work internally with the String constructor function? — Vipinkumar Singh, Jul 30 '18 at 07:50
@Vipinkumar Singh: You do not seem to comprehend the difference between a string value and a string object. https://stackoverflow.com/questions/5750656/whats-the-point-of-new-stringx-in-javascript — Lain, Jul 30 '18 at 09:17

score 1 · Answer 1 · edited Jul 30 '18 at 08:02

1

It doesn't.

You're just misinterpreting the console's visualisation of a string object and assuming it is expressing it in the form of object literal syntax. If it would, you would see:

 { 0: "h", 1: "e", 2: "l", 3: "l", 4: "o", length: 5, __proto__: String }

But thats certainly quite unreadable, so they probably changed the way of visualizing to make it easier to read.

edited Jul 30 '18 at 08:02

Jonas Wilms

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answered Jul 30 '18 at 07:48

Quentin

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How does the String constructor function in Javascript return an Object without a key?

1 Answers1