Transforming a Typescript class instance into a JavaScript object

Question

Transforming a Typescript class instance into a JavaScript object

Here is the code snippet I am working with:

class A{
    test: string
    constructor(test: string){
        this.test = test
    }
}
const a = new A("hi")
console.log(a)

This is what the output looks like:

A { test: 'hi' }

However, when attempting to upload this as a JavaScript object, it gets rejected since it's not recognized as one. One way to work around this is by using JSON.stringify and JSON.parse methods as shown below:

const someJSON = JSON.stringify(a)
const javascriptObject = JSON.parse(someJSON)

Although this method works, I believe there might be a more efficient solution that does not feel like a workaround. Is there a better way to convert a TypeScript class instance into a plain JavaScript object?

javascript typescript

Answer 1

Answer №1

If you prefer a simple JavaScript object over a class instance, you can use the spread operator to copy the properties like this:

class Car {
    constructor(make, model) {
        this.make = make;
        this.model = model;
    }
}

const myCar = new Car("Toyota", "Corolla");
const carCopy = { ...myCar };

console.log('Original car:', myCar);
console.log('Copied car:', carCopy);
console.log('Is carCopy an instance of Car:', carCopy instanceof Car);

Answer 2

If you prefer a simple JavaScript object over a class instance, you can use the spread operator to copy the properties like this:

class Car {
    constructor(make, model) {
        this.make = make;
        this.model = model;
    }
}

const myCar = new Car("Toyota", "Corolla");
const carCopy = { ...myCar };

console.log('Original car:', myCar);
console.log('Copied car:', carCopy);
console.log('Is carCopy an instance of Car:', carCopy instanceof Car);

Answer 3

Answer №2

If you want to explicitly set the prototype of your symbol to the default prototype of objects, you can utilize the Object.setPrototypeOf() method like this:

class A {
    constructor(example) {
        this.example = example;
    }
}

const instanceA = new A("hello");
Object.setPrototypeOf(instanceA, Object.prototype);
console.log({ instanceA, proto: Object.getPrototypeOf(instanceA) });

After running this code, instanceA will be equal to { example: "hello" }.

Answer 4

If you want to explicitly set the prototype of your symbol to the default prototype of objects, you can utilize the Object.setPrototypeOf() method like this:

class A {
    constructor(example) {
        this.example = example;
    }
}

const instanceA = new A("hello");
Object.setPrototypeOf(instanceA, Object.prototype);
console.log({ instanceA, proto: Object.getPrototypeOf(instanceA) });

After running this code, instanceA will be equal to { example: "hello" }.

Answer 5

Answer №3

In preparation for the future, it is advisable to consider adding additional methods to your class. It is possible that certain properties may need to be made private at some point. To facilitate this transition, a method called toObject can be implemented. This method will allow you to interact with data in the required format efficiently.

class B{
      constructor(private _info: string){

      }

      public toObject(){
        //return JSON.parse(JSON.stringify(this));
        //if underscored private variables are desired
        let obj = {};
        Object.keys(this).map((key: string) => {
          obj[key.slice(1)] = this[key];
        });

        return obj;
      }
    }

    const b = new B("hello")
    console.log(b);
    console.log('----------------------');
    console.log(b.toObject());

Answer 6

In preparation for the future, it is advisable to consider adding additional methods to your class. It is possible that certain properties may need to be made private at some point. To facilitate this transition, a method called toObject can be implemented. This method will allow you to interact with data in the required format efficiently.

class B{
      constructor(private _info: string){

      }

      public toObject(){
        //return JSON.parse(JSON.stringify(this));
        //if underscored private variables are desired
        let obj = {};
        Object.keys(this).map((key: string) => {
          obj[key.slice(1)] = this[key];
        });

        return obj;
      }
    }

    const b = new B("hello")
    console.log(b);
    console.log('----------------------');
    console.log(b.toObject());

Transforming a Typescript class instance into a JavaScript object

Answer №1

Answer №2

Answer №3

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