C Primer Plus®, Third Edition

Summary: Using if Statements for Making Choices

Keywords

The keywords for if statements are if and else.

General Comments

In each of the following forms, the statement can be either a simple statement or a compound statement. A "true" expression, more generally, means one with a nonzero value.

Form 1

if (expression)
     statement
					

The statement is executed if the expression is true.

Form 2

if (expression)
     statement1
  else
      statement2
					

If the expression is true, statement1 is executed. Otherwise, statement2 is executed.

Form 3

if (expression1)
   statement1
 else if (expression2)
   statement2
 else
    statement3
					

If expression1 is true, statement1 is executed. If expression1 is false but expression2 is true, statement2 is executed. Otherwise, if both expressions ...