JAVA Tutorial-1

1. Demonstrate HelloWorld Application with Single and Multiple Main in a java program.
2. Write a console program to define and initialize a variable of type byte to 1, and then successively multiply it by 2 and display its value 8 times. Explain the reason for the last result.
3. Write a program that defines a floating-point variable initialized with a dollar value for your income and a second floating-point variable initialized with a value corresponding to a tax rate of 35 percent. Calculate and output the amount of tax you must pay with the Rs. and paisa stored as separate integer values (use two variables of type int to hold the tax, perhaps taxRs and taxPaisa).
4. Write a program that calculate percentage marks of the student if marks of 6 subjects are given.

1. Demonstrate HelloWorld Application with Single and Multiple Main in a java program.

 
   class Hello
   {
     public static void main(String a[])
     {
       System.out.println("Hello Java");
       main();
     }
     public static void main()
     {
       System.out.println("Hello World");
     } 
   }

Output

2. Write a console program to define and initialize a variable of type byte to 1, and then successively multiply it by 2 and display its value 8 times. Explain the reason for the last result.

 
class ByteDemo
{
   public static void main(String ar[])
   {
      byte a=1;
      int i=1;
      while(i<=8)
      { 
         a=(byte)(a*2);
  System.out.println(a);
  i++;
       }
   }
}

Output



Reason : Byte range is -128 to 127, so in this case 64*2=128 but byte range
 upto 127 so it will starts from -128 that's why last two output is -128 and 0

3. Write a program that defines a floating-point variable initialized with a dollar value for your income and a second floating-point variable initialized with a value corresponding to a tax rate of 35 percent. Calculate and output the amount of tax you must pay with the Rs. and paisa stored as separate integer values (use two variables of type int to hold the tax, perhaps taxRs and taxPaisa).

 
class tax
{
   public static void main(String args[])
   {
 float a,b,rs;
 int taxrs,taxpaisa,t;
 a=(float)200.85;
 b=(float)((35.00*a)/100.00);
 rs=(float)(b*67.50);
 taxrs=(int)rs;
 taxpaisa=(int)((rs-taxrs)*100);
 System.out.println("Tax Rate in Dollars="+b);
 System.out.println("Tax Rate in Rs="+taxrs);
 System.out.println("Tax Rate in Paisa="+taxpaisa);
   }
}

Output

4. Write a program that calculate percentage marks of the student if marks of 6 subjects are given.

 
class marks
{
   public static void main(String args[])
   {
 int ma=50,java=60,mp=66,sp=65,ada=65,dbms=70;
 float per;
 System.out.println("Subject Marks");
 System.out.println("Math="+ma);
 System.out.println("java="+java);
 System.out.println("mp="+mp);
 System.out.println("sp="+sp);
 System.out.println("ada="+ada);
 System.out.println("dbms="+dbms);
 per=(float)(((ma+java+mp+sp+ada+dbms)*100)/600);
 System.out.println("Percentage="+per);
   }
}

Output