Many-way Branches

double discount;        
char code = 'B' ;

switch ( code )
{
  case 'A':
    discount = 0.0;
    break;

  case 'B':
    discount = 0.1;
    break;

  case 'C':
    discount = 0.2;
    break;

  default:
    discount = 0.3;
}

Often a program needs to make a choice among several options based on the value of a single expression. For example, a clothing store might offer a discount that depends on the quality of the goods:

• Class 'A' goods are not discounted at all.
• Class 'B' goods are discounted 10%.
• Class 'C' goods are discounted 20%.
• anything else is discounted 30%.

The program fragment does that. A choice is made between four options based on the value in code.

The switch statement looks at the cases to find a match for the value in code.

It then executes the statements between the matching case and the following break. All other cases are skipped. If there is no match, the default case is chosen.

The default case is optional. If present, it must be the last case.

Warning: the complete rules for switch statements are complicated. Read on to get the details.