If you want to declare a constant in Java, you can do so with the final field modifier:
andrew@UBUNTU:~/Java$ cat Constant1.java
public class Constant1
{
public static void main(String args[])
{
final double PI = 3.14;
System.out.println("PI = " + PI);
}
}
andrew@UBUNTU:~/Java$ javac Constant1.java
andrew@UBUNTU:~/Java$ java Constant1
PI = 3.14
andrew@UBUNTU:~/Java$
If you try to change one of these variables, you get a compilation error:
andrew@UBUNTU:~/Java$ cat Constant2.java
public class Constant2
{
public static void main(String args[])
{
final double PI = 3.14;
System.out.println("PI = " + PI);
PI = 22/7;
}
}
andrew@UBUNTU:~/Java$ javac Constant2.java
Constant2.java:7: cannot assign a value to final variable PI
PI = 22/7;
^
1 error
andrew@UBUNTU:~/Java$
