Contents - Cultural View

Java syntax 189
Foo.doSomething();
Modifiers
Modifiers are keywords used to modify declarations of types and type members. Most notably there is a sub-group
containing the access modifiers.
• abstract - Specifies that a class only serves as a base class and cannot be instantiated.
• static - Used only for member classes, specifies that the member class does not belong to a specific instance of
the containing class.
• final - Classes marked as final cannot be extended from and cannot have any subclasses.
• strictfp - Specifies that all floating-point operations must be carried out conforming to IEEE 754 and forbids
using enhanced precision to store intermediate results.
Access modifiers
The access modifiers, or inheritance modifiers, set the accessibility of classes, methods, and other members.
Members marked as public can be reached from anywhere. If a class or its member does not have any modifiers,
default access is assumed.
public class Foo {
}
int do() {
}
return 0;
private class Bar {
}
The following table shows whether code within a class has access to the class or method depending on the accessing
class location and the modifier for the accessed class or class member:
Modifier Same
class
Other class inside the same
package
Subclass inside another
package
Non-subclass inside another
private yes no no no
default (package
private)
package
yes yes no no
protected yes yes yes no
public yes yes yes yes
Constructors
A constructor is a special method that is called when an object is initialized. Its purpose is to initialize the members
of the object. The main differences between constructors and ordinary methods are that constructors are named after
the class and never return anything. They may take parameters as any common method.
class Foo {
}
Foo() {
}
//Initialization