javascript - Dynamically choose class from string - "MyClassName" -> MyClassName -

this question has answer here:

• create object string in javasscript ecmascript 6 4 answers

i use babel.js traspiler write es6 code.

i have string containing class name. want class can instantiate. how?

i tried:

eval("myclassname") -> :( window["myclassname"] -> :( 

any ideas?

you can:

since babeljs have transpile es5 module loader, simple (depending on module format you've specified @ transpile time):

const myclassname = require("myclassname"); const obj = new myclassname(); 

however not es6, transpiled es5. code not work in true es6 environments.

in es6 environment class syntactic sugar function, there no reason cannot do:

// class definition class myclassname { } // pollute global scope (global || window).myclassname = myclassname; 

and load so:

const instance = new (window || global)["myclassname"](); 

but in doing you've broken major feature modules give in first place.

you should:

create factory class. in majority of cases, amount of classes can instantiate finite. should create factory function gives class instance based on string:

import myclassname "./myclassname" class myfactory {     static getinstance(value) {         if(value === "myclassname") {             return new myclassname();         }         throw new error(`could not instantiate ${value}`);     } } 

which used as:

import myfactory "./myfactory"; const instance = myfactory.getinstance("myclassname"); 

obviously expand on use map instead of string of if statements, idea.