Basics of Java Programming - Part 1

• Datatypes in Java

• int 4 bytes
• short int 2 bytes
• long int 8 bytes
• byte 1 byte
• float  4 bytes
• double 8 bytes
• char 2 bytes

• Character to ASCII conversion in JAVA

        class CharToASCII {

public static void main(String a[]) {

char c1 = 'A';

char c2 = 'a';

System.out.print((int)c1); // OUTPUT: 65

System.out.print((int)c2); // OUTPUT: 97

System.out.print((char)66); // OUTPUT: B  --> ASCII to int conversion

          }

       }

• "printf" is also available in JAVA

          class PrintfInJava {

            public static void main(String a[]) {

int i = 4;

int j = 7;

                 int k = i+j;

System.out.printf("Addition of %d and %d is %d", i, j, k); // OUTPUT: 65

           }

       }

• Binary Literals

        public class BinaryLiterals {

public static void main(String a[]) {

// i, j and k are same representation

int i = 0b10000000;

int j = 0B10000000;

int k = 0b100_00_000;

System.out.printf("value of i is %d, j is %d and k is %d", i, j, k); 

}

      }

      //OUTPUT: value of i is 128, j is 128 and k is 128

• Post increment

       public class PostIncrement {

public static void main(String a[]) {

int i = 10;

i = i++;

/*

           i = i++; is similar to:

          int temp;

          temp = i;

           i++;

           i = temp;

         //OUTPUT 10

*/

System.out.println("value of i is " + i );

int j = 7;

int k;

k = j++;

System.out.println("\n value of k is: "+ k + " and j is: "+ j );

}

     }

     //OUTPUT: 

     // value of i is 10

    //  value of k is: 7 and j is: 8

• Bitwise left and right shift operator

       public class LeftAndRightShiftOps {

public static void main(String a[]) {

int i = 25; // Binary  1 1 0 0 1

int j = i << 2; // Binary 1 1 0 0 1 0 0

int k = i >> 2; // Binary 1 1 0

System.out.printf("value of j is %d \nvalue of k is %d", j, k);

}

     }

    //OUTPUT: 

   // value of j is 100 

  // value of k is 6