The prototype property allows to add new properties and methods to the existing JavaScript object types. There are two examples to describe the JavaScript String prototype property.
Syntax:
object.prototype.name = value
Return Value: It returns a reference to the String.prototype object.
Example 1: This example adds a property salary to the all objects.
<!DOCTYPE HTML> < html > < head > < title > JavaScript String prototype Property </ title > </ head > < body style = "text-align:center;" > < h1 >GeeksForGeeks</ h1 > < p id = "GFG_UP" ></ p > < button onclick = "GFG_Fun();" > Click Here </ button > < p id = "GFG_DOWN" ></ p > < script > var up = document.getElementById('GFG_UP'); var down = document.getElementById('GFG_DOWN'); function person(name, age) { this.name = name; this.age = age; } var p1 = new person("p1", 24); up.innerHTML = "Click on the button to add " + "a new property to all objects of" + " a given type.< br > " + JSON.stringify(p1); function GFG_Fun() { person.prototype.salary = 1000; down.innerHTML = p1.salary; } </ script > </ body > </ html > |
Output:
Example 2: This example adds a method info to the all objects.
<!DOCTYPE HTML> < html > < head > < title > JavaScript String prototype Property </ title > </ head > < body style = "text-align:center;" > < h1 >GeeksForGeeks</ h1 > < p id = "GFG_UP" ></ p > < button onclick = "GFG_Fun();" > Click Here </ button > < p id = "GFG_DOWN" ></ p > < script > var up = document.getElementById('GFG_UP'); var down = document.getElementById('GFG_DOWN'); function person(name, age) { this.name = name; this.age = age; } var p1 = new person("p1", 22); up.innerHTML = "Click on the button to add" + " a new property to all objects " + "of a given type.< br > " + JSON.stringify(p1); function getData(name, age) { return "Information of person < br >Name - '" + name + "'< br >Age - " + age; } function GFG_Fun() { person.prototype.info = getData(p1.name, p1.age); down.innerHTML = p1.info; } </ script > </ body > </ html > |
Output: