1. 1 Announcements B7 tutorial today 1100-1200 in CS103 –In CSE department –Ask at entry desk for direction to CS103

2. 2 Unary and binary operators Operators acting on a single variable or an expression are called unary operators –Example: logical NOT, unary plus, unary minus boolean x = true; boolean y = !x;// unary logical NOT int z = 23; int w = +z;// unary plus int k = -z;// unary minus or negation int j = -z-20;// what is j: -43 or -3? int r = -(z-20);// what is r?

3. 3 Unary and binary operators Operators acting on two variables or expressions are called binary operators –Example: add (+), subtract (-), multiply (*), … –Example of boolean operators (unary and binary) boolean x = true; boolean y = !x && x; boolean z = !(y || x); boolean w = !y && !x; boolean k = !(y && x); boolean p = !y || !x;

4. 4 Examples Instructor: Mainak Chaudhuri mainakc@cse.iitk.ac.in

5. 5 Printing characters class printcharacter{ public static void main(String arg[]){ char grade=‘A’; System.out.println(grade);// prints A System.out.println((int)grade); // prints 65 System.out.println(grade+’B’);// prints 131 System.out.println(grade+1);// prints 66 System.out.println((char)(grade+1));// prints B } Notice the type cast Notice the automatic type conversion

6. 6 Printing characters class printcharacter{ public static void main(String arg[]){ char grade=‘A’; System.out.println(grade++);// prints A System.out.println(grade); // prints B } Post-increment

7. 7 Printing characters class printcharacter{ public static void main(String arg[]){ char grade=‘A’; System.out.println(++grade);// prints B System.out.println(grade); // prints B } Pre-increment

8. 8 More type cast class castExample{ public static void main(String arg[]){ double x=Math.PI;// Call to Math class double y=-Math.PI; System.out.println(“Value of PI is: ” + x); System.out.println((int)x); // prints 3 System.out.println((int)y); // prints -3 }

9. 9 Celsius to Fahrenheit class CToF{ public static void main(String arg[]){ double C = 40; double F; F = (C/5.0)*9.0 + 32; System.out.println(C + “Celsius is same as ” + F + “ Fahrenheit”); }