Class constructor, is it possible to set a property to be an object?

JavaScript
1

You use classes to make new objects which share similar construction. What if you want some of those object properties to be objects as well? For example:

const obj={
     prop: 'string',
     obj: { prop: 5 }
}

Can you make a class which creates similar objects while passing it a string and number value?

2

Definitely. Your class properties can hold any type of JS values. Why don’t you try creating a simple class with a constructor to show us what you are trying to do and if it doesn’t work paste your code here and we can help you troubleshoot.

3 
class Example{
    constructor(string, num){
        this.obj={
            id:`${num}-id`, text: string+' '+num
        }
        this.obj2={
            number: num, class: string
        }
    }
}

Ok i made up this as an example. When i use new to create an object and type it in the console i dont get the expected result. I am also trying to include the props in more flexible way and i aint sure how attainable is that.

4

I’m not sure I understand what result you are expecting? The class code you have here looks good to me. I ran it on my computer and it works as expected. Can you give more details about what exactly you are trying to do?

1 Like
5

Yeah, it gets the result that I would expect:

class Example{
    constructor(string, num){
        this.obj={
            id:`${num}-id`, text: string+' '+num
        }
        this.obj2={
            number: num, class: string
        }
    }
}

const myEx = new Example('apple', 123);

console.log(JSON.stringify(myEx, null, 2));
// {
//   "obj": {
//     "id": "123-id",
//     "text": "apple 123"
//   },
//   "obj2": {
//     "number": 123,
//     "class": "apple"
//   }
// }

To reiterate what bbsmooth is asking… What result are you getting and what did you expect instead?

1 Like
6

sorry guys, i think i didnt read my console correct. So i did write it correctly after all?

7

It is proper JS, no syntax errors or anything. Whether it is working correctly for what you want to do? Only you can know that :slight_smile: But if you want to explain in more detail what you are trying to do then we might be able to offer suggestions if needed.

8

its a template to produce objects with data for similar elements in my app, holding id’s, text content etc and a lot of the values and code is repetitive beside a value and a key-word, so i wanted to test myself and come up with a constructor about it. They will also share functions among them, so it will be another challenge to add a method. I will post again if i come to a dead end

9

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