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constructor Property

Specifies the function that creates an object.



Required. The name of an object or function.

The constructor property is a member of the prototype of every object that has a prototype. This includes all intrinsic JScript objects except the arguments, Enumerator, Error, Global, Math, RegExp, Regular Expression, and VBArray objects. The constructor property contains a reference to the function that constructs instances of that particular object.

Class-based objects do not have a constructor property.

The following example illustrates the use of the constructor property.

function testObject(ob)
    if (ob.constructor == String)
        return ("Object is a String.");
    else if (ob.constructor == MyFunc)
        return ("Object is constructed from MyFunc.");
        return ("Object is neither a String nor constructed from MyFunc.");

// A constructor function.
function MyFunc() {
    // Body of function.

var x = new String("Hi");

var y = new MyFunc;

The output of this program is:

Object is a String.
Object is constructed from MyFunc.