The switch Statement

The switch Statement

üThe switch statement provides another means to decide which statement to execute next

üThe switch statement evaluates an expression, then attempts to match the result to one of several possible cases

üThe expression of a switch statement must result in an integral type, meaning an int or a char

üEach case contains a value and a list of statements

üThe flow of control transfers to statement associated with the first value that matches.

The switch Statement

üThe general syntax of a switch statement is:

switch

and

case

are

reserved

words

switch (expression) {

    case value1:

        statement-list1

    case value2:

        statement-list2

    case value3:

        statement-list3

}

If expression

matches value2,

control jumps

from here

The switch Statement

üOften a break statement is used as the last statement in each case's statement list

üA break statement causes control to transfer to the end of the switch statement

üIf a break statement is not used, the flow of control will continue into the next case

üSometimes this can be appropriate, but usually we want to execute only the statements associated with one case.

The switch Statement

üA switch statement can have an optional default case

üThe default case has no associated value and simply 

uses the reserved word default

üIf the default case is present, control will transfer to it if

 no other case value matches

üIf there is no default case, and no other value matches, 

control falls through to the statement after the switch.

Switch example

char letter = 'b';

switch (letter) {

    case 'a':

        System.out.println("A");

        break;

    case 'b':

        System.out.println("B");

        break;

    case 'c':

        System.out.println("C");

        break;

    case 'd':

        System.out.println("D");

        break;

    default:

        System.out.println(”?");

}