JavaScript String prototype properties

　JavaScript String Object

prototypeProperties allow you to add properties and methods to the String object.

Note:Prototype is a global property that is available for almost all objects (Number, Array, String, and Date, etc.).

Syntax:

String.prototype.name　=　value

Create a new string method that returns the number of vowels in the given text:

String.prototype.countVowels　=　function()　{
var　x　=　this.match(/[aeiou]/gi);
return　　(x　===　null　?　0　:　x.length);
};

Using new methods on strings:

var　str　=　'Hello　world';
str.countVowels();　　//　return　3

Test and see‹/›

Browser Compatibility

All browsers fully support the prototype property:

　JavaScript String Object