1. Data Types and Expressions2
C# Programming: From Problem Analysis to Program Design
4th Edition
C# Programming: From Problem Analysis to Program Design

2. Integral Data Types (Integers)
Primary difference
How much storage is needed
Whether a negative value can be stored
Includes number of types
byte & sbyte
char
int & uint
long & ulong
short & ushort
C# Programming: From Problem Analysis to Program Design

3. Data Types Table 2-9 Values and sizes for integral types
C# Programming: From Problem Analysis to Program Design

4. Examples of Integral Variable Declarations
int studentCount; // number of students in the class
int ageOfStudent = 20; // age - originally initialized to 20
int numberOfExams; // number of exams
int coursesEnrolled; // number of courses enrolled
C# Programming: From Problem Analysis to Program Design

5. Floating-Point Types May be in scientific notation with an exponent
n.ne±P
3.2e+5 is equivalent to 320,000
1.76e-3 is equivalent to
OR in standard decimal notation
Default type is double
Table Values and sizes for floating-point types
C# Programming: From Problem Analysis to Program Design

6. Examples of Floating-Point Declarations
double extraPerson = 3.50; // extraPerson originally set
// to 3.50
double averageScore = 70.0; // averageScore originally set
// to 70.0
double priceOfTicket; // cost of a movie ticket
double gradePointAverage; // grade point average
float totalAmount = 23.57f; // note the f must be placed after
// the value for float types
C# Programming: From Problem Analysis to Program Design

7. Decimal Types Monetary data items
As with the float, must attach the suffix ‘m’ or ‘M’ onto the end of a number to indicate decimal
Float attach ‘f’ or ‘F’
Table Value and size for decimal data type
Examples
decimal endowmentAmount = M;
decimal deficit;
C# Programming: From Problem Analysis to Program Design

8. Boolean Variables Based on true/false, on/off logic
Boolean type in C# → bool
Does not accept integer values such as 0, 1, or -1
bool undergraduateStudent;
bool moreData = true;
C# Programming: From Problem Analysis to Program Design

9. Strings Reference type Represents a string of Unicode characters
string studentName;
string courseName = "Programming I";
string twoLines = "Line1\nLine2";
C# Programming: From Problem Analysis to Program Design

10. Making Data Constant Add the keyword const to a declaration
Value cannot be changed
Standard naming convention
Syntax
const type identifier = expression;
const double TAX_RATE = ;
const int SPEED = 70;
const char HIGHEST_GRADE = 'A';
C# Programming: From Problem Analysis to Program Design

11. Assignment Statements
Used to change the value of the variable
Assignment operator (=)
Syntax
variable = expression;
Expression can be:
Another variable
Compatible literal value
Mathematical equation
Call to a method that returns a compatible value
Combination of one or more items in this list
C# Programming: From Problem Analysis to Program Design

12. Examples of Assignment Statements
int numberOfMinutes,
count,
minIntValue;
numberOfMinutes = 45;
count = 0;
minIntValue = ;
C# Programming: From Problem Analysis to Program Design

13. Examples of Assignment Statements
char firstInitial,
yearInSchool,
punctuation;
enterKey,
lastChar;
firstInitial = 'B';
yearInSchool = '1';
punctuation = '; ';
enterKey = '\n'; // newline escape character
lastChar = '\u005A'; // Unicode character 'Z'
C# Programming: From Problem Analysis to Program Design

14. Examples of Assignment Statements (continued)
double accountBalance,
weight;
bool isFinished;
accountBalance = ;
weight = 1.7E-3; //scientific notation may be used
isFinished = false; //declared previously as a bool
//Notice – no quotes used
C# Programming: From Problem Analysis to Program Design

15. Examples of Assignment Statements (continued)
decimal amountOwed,
deficitValue;
amountOwed = m; // m or M must be suffixed to
// decimal data types
deficitValue = M;
C# Programming: From Problem Analysis to Program Design

16. Examples of Assignment Statements (continued)
string aSaying, fileLocation;
aSaying = "First day of the rest of your life!\n";
fileLocation "C:\CSharpProjects\Chapter2";
@ placed before a string literal signals that the characters inside the double quotation marks should be interpreted verbatim --- No need to use escape characters
C# Programming: From Problem Analysis to Program Design

17. Examples of Assignment Statements (continued)
Figure 2-7 Impact of assignment statement
C# Programming: From Problem Analysis to Program Design

18. Arithmetic Operations
Simplest form of an assignment statement
resultVariable = operand1 operator operand2;
Readability
Space before and after every operator
Table Basic arithmetic operators
C# Programming: From Problem Analysis to Program Design

19. Basic Arithmetic Operations
Figure 2-8 Result of 67 % 3
Modulus operator with negative values
Sign of the dividend determines the result
-3 % 5 = -3; % -3 = 2; % -3 = -3;
C# Programming: From Problem Analysis to Program Design

20. Basic Arithmetic Operations (continued)
Plus (+) with string Identifiers
Concatenates operand2 onto end of operand1
string result;
string fullName;
string firstName = "Rochelle";
string lastName = "Howard";
fullName = firstName + " " + lastName;
C# Programming: From Problem Analysis to Program Design

21. Concatenation Figure 2-9 String concatenation
C# Programming: From Problem Analysis to Program Design

22. Basic Arithmetic Operations (continued)
Increment and Decrement Operations
Unary operator
num++; // num = num + 1;
--value1; // value = value – 1;
Preincrement/predecrement versus post
int num = 100;
Console.WriteLine(num++); // Displays 100
Console.WriteLine(num); // Display 101
Console.WriteLine(++num); // Displays 102
C# Programming: From Problem Analysis to Program Design

23. Basic Arithmetic Operations (continued)
Figure Declaration of value type variables
C# Programming: From Problem Analysis to Program Design

24. Basic Arithmetic Operations (continued)
Figure Change in memory after count++; statement executed
C# Programming: From Problem Analysis to Program Design

25. Basic Arithmetic Operations (continued)
int x = 100;
Console.WriteLine(x++ + " " + ++x);
// Displays
C# Programming: From Problem Analysis to Program Design

26. Basic Arithmetic Operations (continued)
Figure Results after statement is executed
C# Programming: From Problem Analysis to Program Design

27. C# Programming: From Problem Analysis to Program Design