Overview of C# Programming - Illustrated C# 2005 - page 21

Statements
The statements in C# are very similar to those of C and C++. This section will introduce the gen-
eral form of statements; the specific statement forms will be covered in Chapter 9.

Simple Statements
A statement is a source code instruction describing a type or telling the program to perform an
action.

￿A simple statement is terminated by a semicolon.

For example, the following code is a sequence of two simple statements. The first state-
ment defines a variable named var1 and initializes its value to 5 . The second statement prints
the value of variable var1 to the screen.

int var1 = 5;
System.Console.WriteLine("The value of var1 is {0}", var1);

Blocks
A block is a sequence of zero or more statements enclosed by a matching set of curly braces; it
acts as a single syntactic statement.
You can create a block from the set of two statements in the preceding example by enclos-
ing the statements in matching curly braces, as shown in the following code:

{
int var1 = 5;
System.Console.WriteLine("The value of var1 is {0}", var1);
}

Some important things to know about blocks are the following:

￿ You can use a block whenever the syntax requires a statement but the action you need

requires more than one simple statement.

￿ Certain program constructs require blocks. In these constructs, you cannot substitute a

simple statement for the block.

￿ Although a simple statement is terminated by a semicolon, a block is not followed by a

semicolon. (Actually, the compiler will allow it—but it's not good style.)

{
↓ Terminating semicolon Terminating semicolon
int var2 = 5; ↓
System.Console.WriteLine("The value of var1 is {0}", var1);
}
↑ No terminating semicolon