CODEWITHSUNDEEP
javascript
Simply Innovative
Simply Innovative

Reputation: 191

Get child function name in parent function method

Function B extends A, How to get B function name in parent function A, when I call parentMethod() on object of B child function object.

function A() {

    this.parentMethod = function() {
         //alert('display B function name');
    }
}

function B() {


}


B.prototype = new A();

var b = new B();  
b.parentMethod();

Upvotes: 2

Views: 1078

Answers (2)

user1188996
user1188996

Reputation:

Simplest Way to do this is:

function A() {

    this.parentMethod = function() {
         alert(this.constructor.name);
    }
}

function B() {

}


B.prototype = new A();  
B.prototype.constructor = B; //Add this line.

var b = new B();  
b.parentMethod();

Now when you call parentMethod it will display B as a constructor name.

Upvotes: 2

Felix Kling
Felix Kling

Reputation: 816334

If you fix the constructor property to point to the correct function (i.e. B)

B.prototype.constructor = B;

Then you can access the name of the constructor function via

this.parentMethod = function() {
     alert(this.constructor.name);
}

Note though that Function.name is a non-standard property and might not work in all browsers. The alternative would be to hardcode the function name by overriding parentMethod or adding a property to the instance with the function name. You could also just use the function reference (this.constructor) directly, depending on what you are trying to achieve.

A better way to setup inheritance is to use Object.create [MDN] and call the parent constructor function in the child constructor function:

function A() {}

A.prototype.parentMethod = function() {};


function B() {
    A.call(this); // call parent constructor
}

B.prototype = Object.create(A.prototype); // establish inheritance
B.prototype.constructor = B;

Upvotes: 0

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