java-入门

package newpackage;

public class Week3_1 {

   public static void main(String[] args) {

       System.out.println("Welcome to Java!");

        System.out.println("Welcome to Computer science!");

         System.out.println("programming is fun");

    }

   

}

第二题：

package newpackage;

 

public class Week3_2 {

   public static void main(String[] args) {

       for(int i=0;i<5;i++){

           System.out.println("Welcome to Java");

        }

    }

   

}

第三题：

package newpackage;

public class Week3_3 {

   public static void main(String[] args) {

       System.out.print((9.5*4.5-2.5*3)/(45.5-3.5));

    }

   

}