====== else ======
<code java>
 if ( condition == true ){
    command;    
 } else {
      // if the "if" condition false
      command;
      }
</code>
check if a condition is true or false

===== example of else=====
<code java>


package plausibilitycheck;

import java.util.Scanner;

public class Plausibilitycheck{

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {

        int celsius;
        double fahrenheit;

        Scanner scan = new Scanner(System.in);

        System.out.print("Please type in Celsius : ");
        celsius = scan.nextInt();

        if (celsius > 0) {

            fahrenheit = celsius * 1.8 + 32;
            System.out.println(celsius + "° Celsius are " + fahrenheit + "° Fahrenheit");
        } else {

            System.out.println("invalid Celsius Value ");
        }

    }
}

</code>

=== output else ===
     Please type in Celsius: 0
     invalid Celsius Value