CODEWITHSUNDEEP
javascriptfunctionconstructor
zlotnleo
zlotnleo

Reputation: 285

Specify .constructor.name to be an arbitrary string

I understand there is a way to have the .constructor.name be different from the variable the constructor is stored in

var Foo = function Bar() {};
console.log(new Foo().constructor.name) // => Bar

I was wondering if there is a hacky way to set an object's .constructor.name to something that wouldn't be a valid JS function name, e.g. "Hello::World".

Setting it directly doesn't seem to work: 

function Foo() {};
Foo.prototype.constructor.name = "Test"
console.log(new Foo().constructor.name) // => Foo

I've tried doing it with the Function constructor, but is uses eval, so the JS has to be valid despite being passed a string.

Upvotes: 1

Views: 165

Answers (1)

Mark
Mark

Reputation: 92440

prototype.constructor.name is defined as non-writable, which means you can't just change it with an assignment. 

var Foo = function Bar() {};
console.log(Object.getOwnPropertyDescriptor(Foo.prototype.constructor, 'name'))

But, as you can see, it is configureable, which means you can redefine it. I have no idea if this is wise, but you can do it like:

var Foo = function Bar() {};

Object.defineProperty(Foo.prototype.constructor, 'name', {value: "Test"})
console.log(new Foo().constructor.name)  // Test

Upvotes: 5

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