In this example we will show how to use final keyword in Java.
Source Code
1) variable modifier
package com.beginner.examples;
public class FinalExample1 {
final double PI = 3.14;
public FinalExample1() {
PI = 3.1415926; //The final field FinalVariableExample.count cannot be assigned
}
}
Output:
Unresolved compilation problem
2) method modifier
package com.beginner.examples;
public class FinalExample2 {
final void test(){
System.out.println("OK");
}
}
class example extends FinalExample2{
//Cannot override the final method from FinalExample2
void test(){
System.out.println("Done");
}
}
Output:
Unresolved compilation problem
3) class modifier
package com.beginner.examples;
public final class FinalExample3 {
final void test(){
System.out.println("OK");
}
}
//The type FinalClassChild cannot subclass the final class FinalExample3
class example extends FinalExample3{
void test(){
System.out.println("Done");
}
}
Output:
Unresolved compilation problem