Java Reference
In-Depth Information
// Inner class starts here
public class Inner {
public void printValue() {
System.out.println("Inner: Value = " + value);
}
} // Inner class ends here
// Instance method for the Outer class
public void printValue() {
System.out.println("Outer: Value = " + value);
}
// Another instance method for the Outer class
public void setValue(int newValue) {
this.value = newValue;
}
}
The
Outer
class has a
private
instance variable called
value
, which is initialized to 1116. It also defines two
instance methods:
printValue()
and
setValue()
. The
Inner
class defines an instance method called
printValue()
,
which prints the value of the
value
instance variable of its enclosing class
Outer
.
Listing 2-14 creates an instance of the
Inner
class and invokes its
printValue()
method. The output shows that
the inner class instance can access the instance variable
value
of its enclosing instance
out
.
Listing 2-14.
Testing an Inner Class That Accesses the Instance Members of its Enclosing Class
// OuterTest.java
package com.jdojo.innerclasses;
public class OuterTest {
public static void main(String[] args) {
Outer out = new Outer();
Outer.Inner in = out.new Inner();
// Print the value
out.printValue();
in.printValue();
// Set a new value
out.setValue(828);
// Print the value
out.printValue();
in.printValue();
}
}
Outer: Value = 1116
Inner: Value = 1116
Outer: Value = 828
Inner: Value = 828
