Access Modifiers

Apex allows you to use the private, protected, public, and global access modifiers when defining methods and variables.

While triggers and anonymous blocks can also use these access modifiers, they are not as useful in smaller portions of Apex. For example, declaring a method as global in an anonymous block does not enable you to call it from outside of that code.

For more information on class access modifiers, see Apex Defining Classes.

Note

Interface methods have no access modifiers. They are always global. For more information, see Interfaces and Extending Classes.

By default, a method or variable is visible only to the Apexwithin the defining class. This is different from Java, where methods and variables are public by default. Apex is more restrictive, and requires you to explicitly specify a method or variable as public in order for it to be available to other classes in the same application namespace (see Namespace Prefix). You can change the level of visibility by using the following access modifiers:

private

This is the default, and means that the method or variable is accessible only within the Apex class in which it is defined. If you do not specify an access modifier, the method or variable is private.

protected

This means that the method or variable is visible to any inner classes in the defining Apex class. You can only use this access modifier for instance methods and member variables. Note that it is strictly more permissive than the default (private) setting, just like Java.

public

This means the method or variable can be used by any Apex in this application or namespace.

Note

In Apex, the public access modifier is not the same as it is in Java. This was done to discourage joining applications, to keep the code for each application separate. In Apex, if you want to make something public like it is in Java, you need to use the global access modifier.

global

This means the method or variable can be used by any Apex script that has access to the class, not just the Apex scripts in the same application. This access modifier should be used for any method that needs to be referenced outside of the application, either in the Force.com Web Services API or by other Apex scripts. If you declare a method or variable as global, you must also declare the class that contains it as global.

Note

Salesforce.com recommends using the global access modifier rarely, if at all. Cross-application dependencies are difficult to maintain.

To use the private, protected, public, or global access modifiers, use the following syntax:

[(none)|private|protected|public|global]  declaration

For example:

private string s1 = '1';

public string gets1() { 
   return this.s1; 
}