1 CS 1430: Programming in C++ Turn in your Quiz1-1

My Home Page URL Go to UWP home page Add “/~yangq” or Search for Qi Yang 2

Installing VS 2012 on Your PC about Deamspark (in Junk folder?) Help section on the web site Go to ITS Help Desk if still issues 3

4 Lab0 Due time: 5 PM, September 3 Grace time: 5 PM, September 8

5 Instructions Coping files Starting a New Project (project folder is created) 9. Adding an Existing CPP file to your project (copy file to the folder created at step 8)...

Lab0 Submit to the Grader Go to My Home Page then to the Grader 6

7 Add Two Numbers In Math S = x + y Or x + y = S

8 Add Two Numbers In C++ Sum = num1 + num2; // This is a comment // Semicolon: Statement terminator // Use meaningful names Sum = num1 + num2;

9 Assignment Operator: = num1 + num2 = Sum; // Valid in C++? // No // Assignment statement MUST // be from right to left Sum = num1 + num2; // Correct! // Not equal

10 Are the two statements the same? Sum = Num1 + Num2; Sum = num1 + num2; // NO! // C++ is case sensitive!

11 Arithmetic Operators Addition: + to compute Sum Subtraction: - to compute Difference Multiplication: * to compute Product Division: / to compute Quotient You MUST use operators to compute in C++!

12 Arithmetic Operators What is ** in C++? result = x ** y; // Not good! What is ^ in C++? result = x ^ y; // Not good! S = x (y + z); //Is it good in C++? //Missing operator! S = x * (y + z); // Good!

13 Programming Style S = x * (y + z); // Good! S = x*(y+z); // What’s the difference? // Is it good in C++? // Yes // Is it good in CS1430 at UWP? // No! // Style! S=x * (y + z); // Not Good! S = x * (y + z); // Good!

14 Semantics, Syntax, and Style total = total + 2; Semantics Increase total by 2 Assignment (right to left) Not equal Syntax Statement terminator Case sensitive Style one space before and after any operator meaningful name

15 Precedence Rules From high to low: ( ) *, / +, -

16 Examples x = * 2; // result: x = (8 - 4) * 2; // result: y = 8 / 4 * 2; // result: y = 8 / (4 * 2); // result:

17 More Examples z = 8 / 4 ^ 2; // No! z = 8 / 4 ** 4; // NO! z = 8 / 4 * 4 // Result: ? X = 5(3 – 7); //Result: ? z = 5 / (2 * 5); // Result: 0.5 or 0?

18 Integer Division vs. Float Division In Math 5 is almost always the same as 5.0 In C++ 5 is almost never the same as 5.0 Why? Store value in computer as bits, bytes. 5 is stored as an integer 5.0 is stored as a float number

19 Integer Division We can only get integers! Long Division! 7 / 5 Quotient: 1 Remainder: 2 5 / 7 Quotient: 0 Remainder: 5

20 Float Division We get float result! Long Division! 7.0 / 5.0 Quotient: / 5.0 (Same) 7.0 / 5 (Same) 5.0 / 7 Quotient: …

21 Quotient (Division) Operator: / Expression 7 / 5 5 / 7 14 / 5 5 / / / 143 Result

22 Remainder (Modular) Operator: % Expression 7 % 5 5 % 7 14 % 5 5 % % % 143 Result

23 Exercises Expression Result 12 % 20 * 3 (12 % 20) * 3 12 * 3 20 % 12 * 3 12 / 20 * 3 20 / 12 * 3 20 / 12 % 3 20 % 12 % 3

24 Why Integer Division? Get $143 from ATM Number of $50 bills: / 50 Amount left after $50 bills: % 50 Number of $10 bills: 4 43 / 10 Amount left after $10 bills: 3 43 % 10 Number of $1 bills: 3

25 Summary Statement Terminator Assignment Operator total = total + num1; // from right to left Arithmetic Operators and Precedence Rules () /, %, * -, + Semantics, Syntax, and Style

26 Quiz point Due beginning of class Wednesday

Visual Studio Demo 27