Course recommendation:

JavaScript String prototype property

prototype Definition and usage

prototype It is a property available to all JavaScript objects.

instance

Properties allow you to add new properties and methods to strings. prototype Using

Properties add new properties to all objects of a given type:
  function employee(name, jobtitle, born) {
  this.name = name;
  this.jobtitle = jobtitle;
}
this.born = born;
employee.prototype.salary = 2000;

try it yourself

const fred = new employee("Fred Flintstone", "Caveman", 1970);

Syntax object.prototype.name =

value

Warning

It is not recommended to change the prototype of objects not under your control.

  • You should not change the prototype of built-in JavaScript data types, such as:
  • Strings
  • Arrays
  • Dates
  • Booleans
  • Function
  • Objects

Please only change the prototype of the object you created yourself.

prototype property

JavaScript prototype Properties allow you to add new properties to an object:

instance

function Person(first, last, age, eyecolor) {
  this.firstName = first;
  this.lastName = last;
  this.eyeColor = eyecolor;
}
Person.prototype.nationality = "English";

try it yourself

browser support

prototype is ECMAScript1 (ES1) feature.

All browsers fully support ES1 (JavaScript 1997):

Chrome IE Edge Firefox Safari Opera
Chrome IE Edge Firefox Safari Opera
Support Support Support Support Support Support

Related Pages

JavaScript String

JavaScript String Methods

JavaScript String Search