Conditional Statements

Multiple Alternatives: If/Else If/Else Statements

Sometimes there are several alternative actions, only one of which should be performed, depending on a set of conditions.

For example, a program might print out different greetings depending on the time of day.

    int hour = aClock.getHour();     // getHour returns 0 - 24
    Greeter host = new Greeter();
    if ( hour < 12 )
    {
        host.sayThis("Good morning.");
    }
    else if ( hour < 17 )
    {
        host.sayThis("Good afternoon.");
    }
    else if ( hour < 20 )
    {
        host.sayThis("Good evening.");
    }
    else
    {
        host.sayThis("Good night.");
    }
    host.sayThis("Welcome to the FormalGreetings Restaurant.");
    // Follow-up code goes here.

Syntax:

• The boolean expressions (conditions to check) are always in parentheses.
• A boolean expression is provided only for an if.
• There can be any number of else if ( <boolean-expression> ) segments.
• The final else does not have a boolean expression provided. (Similarly, in a simple if/else statement, the else statement does not include a boolean expression; else means "in all other conditions".