JS - wrapper object

wrapper object (linked to prototype, heritage)

 

Caution: Some of them may be incorrect. Read at your own risk.

 

Note:

it is about the difference of 'where to store the value', and 'temporary', 'primitive'. 

Scanning for its object with the method I input to refer it accordingly.

 

This is kind of 'temporarily use the Primitive things like method.'

Once I approach to some method with Primitive,

 

 

const aqua = 'mizukami';

 

console.log(aqua.length); // 8

console.log(aqua.toUpperCase()); // MIZUKAMI

 

// Once calling it fisniehd (as wrapper object) and temporary object done his job, it will return the primitive one again.

console.log(typeof aqua); // string

 

This means, wrapper object will temporarily work like method since JS does implicitly create 'temporary object' inside prototype. In that prototype object, it has 'string type - wrapper object'. So, [[StringData]] will store the object which contains its string value.

 

My verdict:

This is somewhat specialised at 'temporarily let primitive to check/work out like how others dynamically use/apply method and do its job.

 

Note:

Wrapper objects

When we treat a primitive value like it was an object (i.e. by accessing properties and methods), JavaScript creates, under the hood, a wrapper to wrap this value and expose it as an object. The JS engine never reuses a wrapper object, giving them to the garbage collector right after a single use.

 

https://programmingwithmosh.com/javascript/javascript-wrapper-objects/