I would like to know how to instantiate a class knowing that the type of the class by a STRING under Nestjs and Typescript. I have done some research using this but I have an error that WINDOWS is not defined.
let paul:string = "Wall";
let test = Object.create(new window[paul].prototype);
console.log(test.constructor.name); //Wall
ReferenceError: window is not defined
What you're trying to do is not only extremely complicated in better-suited languages but I doubt it's even possible in Typescript...
A better solution is to plan the whole thing differently (better) and go with inheritance. your Paul class probably inherits from the Person interface just the same as your Sue class so you instantiate with the parent interface
let me rephrase that... you could instantiate with a
let test: Person
switch(name) {
case 'Paul':
test = new Paul()
}
which would serve your purpose.. My guess is you're trying to do that cause you wanna later do something like
let people: any[] = //...
for(let person of people) {
}
but you should instead do
let people: Person[] = //...
for(let person of people) {
}
and any class that implements the Person interface would be able to fit your people array
But again, if you really need a shit ton of classes all with different names, then it begs the question, do you really need separate classes?
UPDATE: I saw your comment about
WALL, 'Adrien' HOUSE, 'Pierre'
In that case you'd use a switch
let houses: House[] = []
let walls: Wall[] = []
...
switch(key) {
case 'WALL':
walls.push(new Wall(value))
case 'HOUSE':
houses.push(new House(value))
...
}
Without having too much information on what you are actually trying to build it sounds like you want to create generic objects that contain information based on your text file.
If you want to instantiate a class based on what you parsed in your text file, you can use a simple if statement:
let object: any = undefined;
if (parsedString === "Wall) {
object = new Wall();
}
If you actually don't have a wall class and you want to create a "Wall" object, I wonder what the use would be, since it would not have any wall behavior and therefore it is not better than a simple string variable. Since instead of object.constructor.name you could just assign a string with the name to the variable instead of instantiating the empty object.
let objectName: string = "";
objectName = parsedString;
Or if it has to be an object just assign a name property to an empty object:
let myObject: object = {};
myObject.name = parsedString;
I do think you have a design flaw in what you are trying to do and if you can give us a better description I'm sure we can help you out in how to design your software properly to achieve your goal.
Here is more to read on how to dynamically assign properties to objects in Typescript
windowis the global object in browser side JavaScript. It's not clear what you're trying to do at the moment as in, why would you try to use a string to create a class?