How may I change an object with only its reference in Javascript?
var $obj = { original: true }
var $ref = $obj
// Is it possible here to set $obj to {} with only using $ref?
$ref = {} // This doesn't work
console.log($obj)
// => { original: true }
Example usage:
var $objs = {
a: {
wantsToBeAnEmptyObject: true
},
b: {
wantsToBeAnEmptyObject: true
}
}
_.forOwn($objs, (val) => {
val = {}
})
Can anyone help me with this problem?
Is it possible here to set $obj to {} with only using $ref?
It's not possible to change which object $obj refers to using $ref, no. You can change the state of the object they both refer to (adding, updating, or removing properties), but you can't change which object $obj refers to. (Note that removing properties from an object de-optimizes it on most JavaScript engines, making subsequent property access much slower. It doesn't usually matter, since even when "slower" modern engines are still very, very fast. But...)
The usual solution to that is to have $obj refer to an object with a property that refers to the object you want to be able to replace:
var $obj = {obj: { original: true } };
// --------^^^^^--------------------^
var $ref = $obj;
$ref.obj = { replaced: true };
// ^^^^
console.log($obj.obj.replaced) // true
You can use the delete keyword to remove keys from an object, which I think would accomplish what you're looking for.
In your example something like
Object.keys($ref).forEach(key=>delete $ref[key])
would do the trick
ref = {} // This doesn't work is pretty clearly replacing something with a new object, not just deleting properties from the existing one.