1. Friday, December 08, 2006 “Experience is something you don't get until just after you need it.” - Olivier

2. §Numeric data types

3. Declarations and Initialization double dx ; dx=3.5 ; OR double dx=3.5 ;

4. Declarations and Initialization //(comma separated) double a, b, c=5.6, d ; double r1, r2, r3; //(white spaces ignored) /*All declarations and statements must end with semicolon ; */

5. int big=980000; short small; cout<<"big="<<big<<endl; small=big; //don't do this cout<<"small="<<small<<endl;

6. int big=980000; short small; cout<<"big="<<big<<endl; small=big; //don't do this cout<<"small="<<small<<endl; big=980000 small=-3040

7. short small = 980000; cout << small << endl; -3040

8. Character Data l Each character corresponds to a binary code l Most commonly use binary codes are ASCII (American Standard Code for Information Interchange) CharacterASCII CodeInteger Equivalent %010010137 3011001151 A100000165 a110000197 b110001098 c110001199

9. Arithmetic Operators §Addition+ §Subtraction- §Multiplication* §Division/ §Modulus%

10. Arithmetic Operators §Addition+ §Subtraction- §Multiplication* §Division/ §Modulus% l Modulus returns remainder of division between two integers l % cannot be used on float or double

11. l Example 5 % 2 evaluates to ? 10 % 2 evaluates to ?

12. l Example 5 % 2 evaluates to 1 10 % 2 evaluates to 0

13. Arithmetic Operators §Division between two integers results in an integer. §The result is truncated, not rounded

14. Modulo operation 17 / 5 evaluates to 17 % 5 evaluates to

15. Modulo operation 17 / 5 evaluates to 3. 17 % 5 evaluates to 2.

16. §Example: 5/3 evaluates to ? 3/6 evaluates to ?

17. §Example: 5/3 evaluates to 1 3/6 evaluates to 0

18. Priority of Operators 1ParenthesesInner most first 2Unary operatorsRight to left (+ -) 3Binary operatorsLeft to right (* / %) 4Binary operatorsLeft to right (+ -)

19. Precedence §Order of mathematical operations is important. Examples: (3+2)*4 = 5*4 = 20 3+(2*4) = 3 + 8 = 11  * and / evaluated before + and - Example: 3+2*4 evaluated as 3+(2*4)

20. Precedence  If precedence is equal, then evaluate from left to right. Examples: 3+2+5 = 5 + 5 = 10 3*2/5 = 6/5 = 1  Parentheses enforce evaluation order Example: (3+2)*4 = 5*4 = 20

21. Unary operators: +, - §Unary operators: +, - -3, +17 allowed Example: 4*(-3) = -12

22. Assignment Operators =assignment operator Compound Assignment Operators operatorexampleequivalent statement +=x+=2; x=x+2; -=x-=2;x=x-2; *=x*=y;x=x*y; /=x/=y;x=x/y;

23. Example x = 4; x *= 5;

24. Example x = 4; x *= 5; // x = 20

25. Arithmetic Operators §unary operators auto increment ++ –post increment x++; –pre increment ++x; auto decrement - - –post decrement x- -; –pre decrement - -x;

26. x++ is executed after it is used x = 7; y = x++; ++x is also equivalent to x = x+1 ++x executed before it is used x = 7; y = ++x; --x is equivalent to x = x-1 -- works just like ++, but with subtraction instead of addition

27. x++ is executed after it is used x = 7; y = x++; // x = 8, y = 7 ++x is also equivalent to x = x+1 ++x executed before it is used x = 7; y = ++x; // x = 8, y = 8 --x is equivalent to x = x-1 -- works just like ++, but with subtraction instead of addition

28. Shortcuts  n++ equivalent to n = n + 1 read as "add 1 to n"  n-- equivalent to n = n - 1 read as "subtract 1 from n"  s += n equivalent to s = s + n read as "add n to s"  s -= n equivalent to s = s - n read as "subtract n from s