java tools
-------------------
javac
java
javap
appletviewer
javah
jdb
javadoc
// rect program
class Rect
{
int len,bre;
void get(int l,int h)
{
len=l;
bre=h;
}
void area(){
System.out.println("Area ="+len*bre)
}
public static void main(String a[])
{
Rect r=new Rect();
r.area();
r.get(10,11);
r.area();
}
}
-------------------------17-8-24
import java.lang.Math;
public class Main
{
public static double PI=3.14F;
public static void main(String[] args) {
System.out.println(Math.sqrt(4));
System.out.println(Math.ceil(4.3));
System.out.println(Math.floor(4.3));
System.out.println(PI);
}
}
2.0
5.0
4.0
3.140000104904175
--------------------------------------------------------
import java.lang.Math;
class A{
final void dis(){}
}
class B extends A
{
void dis(){}
}
output:
Main.java:10: error: dis() in B cannot override dis() in A
void dis(){}
^
overridden method is final
1 error
-----------------------------------------------------
import java.lang.Math;
final class A{
void dis(){}
}
class B extends A
{
void dis(){}
}
public class Main
{
public static void main(String[]a)
{
B bobj=new B();
bobj.dis();
}
}
output:
Main.java:8: error: cannot inherit from final A
class B extends A
^
1 error
