prototype

Summary

Returns a reference to the prototype for a class of string.

Syntax

string.prototype

Examples

The string argument is the name of a string.

Use the prototype property to provide a base set of functionality to a class of objects. New instances of an object “inherit” the behavior of the prototype assigned to that object.

For example, to add a method to the String object that returns the value of the last element of the string, declare the function, add it to String.prototype , and then use it.

function string_last( ){
    return this.charAt(this.length - 1);
}
String.prototype.last = string_last;
var myString = new String("every good boy does fine");
document.write(myString.last());

// Output:
// e

Remarks

All intrinsic JavaScript objects have a prototype property that is read-only. Properties and methods may be added to the prototype, but the object may not be assigned a different prototype. However, user-defined objects may be assigned a new prototype.

The method and property lists for each intrinsic object in this language reference indicate which ones are part of the object’s prototype, and which are not.

Attributions

• Microsoft Developer Network: Article