Java Inner Classes
In Java, it is also possible to nest classes (a class within a class). The purpose of nested classes is to group classes that belong together, which makes your code more readable and maintainable.
Example
class OuterClass {
int x = 10;
class InnerClass {
int y = 5;
}
}
public class Main {
public static void main(String[] args) {
OuterClass myOuter = new OuterClass();
OuterClass.InnerClass myInner = myOuter.new InnerClass();
System.out.println(myInner.y + myOuter.x);
}
}// Outputs 15 (5 + 10)
Private Inner Class
class OuterClass {
int x = 10;
private class InnerClass {
int y = 5;
}
}Attempting to access a private inner class from an outside class will result in an error.
Static Inner Class
class OuterClass {
int x = 10;
static class InnerClass {
int y = 5;
}
}Access Outer Class From Inner Class
class OuterClass {
int x = 10;
class InnerClass {
public int myInnerMethod() {
return x;
}
}
}