Using Object.create () to create objects in JavaScript introduce _javascript tips

In addition to the use of literal and new operators for object creation, Object.create () can also be used in the ECMAScript 5 standard. The Object.create () function accepts 2 objects as arguments: The first object is required, represents the prototype of the object being created, and the second object is optional, defining the properties of the object being created (for example, writable, enumerable).

Copy Code code as follows:

var o = object.create ({x:1, y:7});
Console.log (o);//object {x=1, y=7}
Console.log (o.__proto__);//object {x=1, y=7}

Calling Object.create () with NULL as the first argument generates an object without prototype that will not have any basic object attributes (for example, the + operator will throw an exception for this object because there is no ToString () method):

Copy Code code as follows:

var O2 = object.create (null);
Console.log ("It is" + O2);//type Error, can ' t convert O2 to primitive Type

For browsers that support only the ECMAScript 3 standard, you can use the Douglas Crockford method for Object.create () operations:

Copy Code code as follows:

if (typeof object.create!== ' function ') {
Object.create = function (o) {
function F () {}
F.prototype = O;
return new F ();
};
}
NewObject = Object.create (Oldobject);