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Chapter 2

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Chapter 2
Working with Variables, Operators, and Expressions
After completing this chapter, you will be able to:

  • Understand statements, identifiers, and keywords.

  • Use variables to store information.

  • Work with primitive data types.

  • Use arithmetic operators such as the plus sign (+) and the minus sign (–).

  • Increment and decrement variables.

In Chapter 1, “Welcome to

C# 2005

,” you learned how to use the Microsoft Visual Studio 2005 programming environment to build and run a console program and a Windows Forms application. In this chapter, you’ll be introduced to the elements of Microsoft Visual

C# 2005

syntax and semantics, including statements, keywords, and identifiers. You’ll study the primitive types that are built into the

C# 2005

language and the characteristics of the values that each type holds. You’ll also see how to declare and use local variables (variables that exist only within a function or other small section of code), learn about the arithmetic operators that

C# 2005

provides, learn how to use operators to manipulate values, and learn how to control expressions containing two or more operators.

the following is :

Chapter 2 Quick Reference

To

Do this

Declare a variable

Write the name of the data type, followed by the name of the variable, followed by a semicolon. For example: 

int outcome;

Change the value of a variable

Write the name of the variable on the left, followed by the assignment operator, followed by the expression calculating the new value, followed by a semicolon. For example: 

outcome = 42;

Convert a

string

to an

int

Call the

System.Int32.Parse

method. For example: 

System.Int32.Parse("42");

Override precedence

Use parentheses in the expression to force operands to bind to specific operators. For example: 

(3 + 4) * 5

Increment or decrement a variable

Use the ++ or <;$MI><;$MI> operator. For example: 

count++;

 

count = count + 1;