Statements

A statement is either:

• a simple statement
• a null statement
• a control statement
• a block or compound statement

Simple Statement

FORM: expression ;

EXAMPLE:    y = 7;

EXAMPLE:    printf("Hello world!\n");

Null Statement

FORM: ;

EXAMPLE: ;

NOTE: The null statement is rarely used, but it is a legal statement which means to do nothing. It usually causes problems for new C programmers. For example, the following code compiles and executes, but does not produce the desired effect


/* an unintentional null statement */ while (i > 0); { printf ("The value of i is %d\n", i); i--; }

Block

{ S₁ S₂ S₃ ... S_n } where the S_i are statements enclosed with braces

Control Statement

an if, for, while, ...

What about semicolons ?

• In C, the semicolon is used to terminate a simple statement
• In Pascal, the semicolon separates statements

So that's the rule for semicolons!