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I am unable to call private or non static method from static method in class, below is the example

class a {
 fun1(){
  console.log('fun1');
 }
 static staticfun(){
  console.log('staticfun');
  this.fun1();
 }
}

a.staticfun();

I am trying to expose only staticfun method which internally calls all private methods, but this gives me this.fun1 is not a function. I tried to find many ways to find it with 'this', but it does work.

How do I call private instance methods inside static methods?

I am unable to call private or non static method from static method in class, below is the example

class a {
 fun1(){
  console.log('fun1');
 }
 static staticfun(){
  console.log('staticfun');
  this.fun1();
 }
}

a.staticfun();

I am trying to expose only staticfun method which internally calls all private methods, but this gives me this.fun1 is not a function. I tried to find many ways to find it with 'this', but it does work.

How do I call private instance methods inside static methods?

  • javascript
  • jquery
  • oop
Share Improve this question edited Oct 23, 2018 at 10:52 Blue 22.9k7 gold badges66 silver badges98 bronze badges asked Oct 23, 2018 at 10:36 Tapan DaveTapan Dave 2731 gold badge3 silver badges17 bronze badges 4
  • There are no "private" methods in JavaScript. Do you mean instance methods? – Bergi Commented Oct 23, 2018 at 10:48
  • It's unclear in your example, but is there a reason why you can't just make fun1 static? – Bergi Commented Oct 23, 2018 at 10:48
  • i am creating node js micro service where i am returning promise from module.exports {return new promise { promise.all().then(r=>fun2).then(r=> fun2)....at last i resolve()}} there i want to make all the promise and function to be wrapped inside class and function should not expose outside the class like modules.exports = {class a{static promise(){.....} fun1(){} fun2(){}} return a.promise()} – Tapan Dave Commented Oct 23, 2018 at 12:53
  • 1 a) avoid the Promise constructor antipattern b) there is no reason to wrap anything in class syntax if you don't need multiple instances – Bergi Commented Oct 23, 2018 at 13:13
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3 Answers 3

Reset to default 5

Another way is to call the function directly from the class prototype (meaning literally the prototype property, not __proto__), if you want to avoid instantiating it.

class a {
 fun1(){
  console.log('fun1');
 }
 static staticfun(){
  console.log('staticfun');
  this.prototype.fun1();
 }
}

a.staticfun();

fun1 is not a static function, so you need to define a new instance of the a class in order to call it:

class a {
  fun1() {
    console.log('fun1');
  }

  static staticfun() {
    console.log('staticfun');
    
    new this().fun1();
  }
}

a.staticfun();

You should note that this is not good practice, though. You shouldn't have a static method relying on non-static logic.

A workaround would be to pass an instance of a to the static function, but that pletely defies the point of having a static method in the first place.

First, read this SO question

It's possible, You can create an instance of class a and then invoke from the instance the method fun1.

Although, There is no sense to call a non-static method from a static one.

static means that this method belong to the object (not to the instance)

class a {
 fun1(){
  console.log('fun1');
 }
 static staticfun(){
  console.log('staticfun');
  const classInstance = new a()
  classInstance.fun1();
 }
}

a.staticfun();

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