I'm wondering if there is a standard way to re-initialize, or re-construct a class instance without creating a new instance all together.

Let's say I have a TestClass instance:

class TestClass {
  constructor() {
    this.x=0;
    this.y=50;
    this.z=200;
  }
}

var testClassInstance=new TestClass();

And basically, overtime I tweak some of it's values.

testClassInstance.x+=250;
testClassInstance.y-=20;

Then later on I want to reset all of its values to whatever was defined when the instance was created. I'm wondering if there is a way to then basically reinitialize it, without creating an entirely new instance?

Is something like

testClassInstance.constructor()

safe and reliable?

I'm wondering if there is a standard way to re-initialize, or re-construct a class instance without creating a new instance all together.

Let's say I have a TestClass instance:

class TestClass {
  constructor() {
    this.x=0;
    this.y=50;
    this.z=200;
  }
}

var testClassInstance=new TestClass();

And basically, overtime I tweak some of it's values.

testClassInstance.x+=250;
testClassInstance.y-=20;

Then later on I want to reset all of its values to whatever was defined when the instance was created. I'm wondering if there is a way to then basically reinitialize it, without creating an entirely new instance?

Is something like

testClassInstance.constructor()

safe and reliable?

• javascript

• 1 you could add a function to the class that resets the values and call this instead of constructor() – john Smith Commented Feb 2, 2018 at 0:14
• Why don't you just create another method, let's say reset(), that restores whatever the initial values were. – alanfcm Commented Feb 2, 2018 at 0:14
• There's a nice answer already, so I won't get in the way. I am curious, though, why do you need this functionality? – Zlatko Commented Feb 2, 2018 at 0:16
• Your question is totally unclear, you're talking about class, but you want to reset objects. – Ele Commented Feb 2, 2018 at 0:20
• @Zlatko I should've been more specific. I'm realizing this isn't the actual info I need, but regardless, still useful answers. I'm working with the THREEjs orbit controls, and I need to enable/disable them. But looking at it now, this question isn't relevent to it's syntax. – Gage Hendy Ya Boy Commented Feb 2, 2018 at 0:21

2 Answers 2

class TestClass {
  constructor() {
    this.reset();
  }

  reset(){
    this.x=0;
    this.y=50;
    this.z=200;
  }
}

const myTestClass = new TestClass();
myTestClass.x = 5;
console.log(myTestClass.x); // 5
myTestClass.reset();
console.log(myTestClass.x); // 0

This answer was generated because of the first version of this question.

Your class is never modified. The class is an implementation, what you modify are the instances created using that implementation.

Look this code snippet:

class TestClass {
  constructor() {
    this.x=0;
    this.y=50;
    this.z=200;
  }
}

var testClassInstance=new TestClass();

testClassInstance.x+=250;
testClassInstance.y-=20;

console.log(testClassInstance.x);
console.log(testClassInstance.y);

var anotherTestClassInstance=new TestClass();

console.log(anotherTestClassInstance.x);
console.log(anotherTestClassInstance.y);