how to compile and run java programs

you have to set path first---
for this
click on Mycomputer->properties->advanced->environmentvariables->pselect new paste the url of bin file C:\Program Files\Java\jdk1.7.0\bin in path and click okk.

then write first the program given below in a note pad

class Example
{
 public static void main(String args[])
 {
 int var1;  // this declares a variable
 int var2; // this declares another variable
var1 = 1024; // this assigns 1024 to var1
 System.out.println("var1 contains " + var1);
 var2 = var1 / 2;
 System.out.print("var2 contains var1 / 2: ");
 System.out.println(var2);
}
 }

then 1.compile by typing  "javac filename.java"  in command prompt
        2. run by typing "java filename" in command prompt
in the above example for a correct output you must put filename and class name to be same  for eg-the filename for the above program is Example.java


Predicted Output: var2 contains var1 / 2: 512

then