switch statement¶

Use the switch statement to pass control to a case which matches the result of the switch_expression. If no case satisfies the condition, the default case is executed.

syntax:

(switch switch_expression
        (case1
                code_block_1
                code_block_2
                ...
        )
        (case2
                code_block_1
                code_block_2
                ...
        )
        .
        .
        .
        (else
                code_block_1
                code_block_2
                ...
        )
)

Example using the switch statement - prints “01.....7....C........” to the screen:

(for ((= i 0)) (< i 20) ((++ i))
        (switch i
                (0
                        (Display "0" dsCOLOR clLIME)
                )
                (1
                        (Display "1" dsCOLOR clBLUE)
                )
                (7
                        (Display "7" dsCOLOR clYELLOW)
                )
                (12
                        (Display "C" dsCOLOR clCYAN)
                )
                (else
                        (Display "." dsCOLOR clWHITE)
                )
        )
)

Switch statements can also be evaluated as expressions:

; Set direction based on the key pressed.
(= direction
        (switch (pEvent message?)
                (KEY_W
                        UP
                )
                (KEY_S
                        DOWN
                )
                (KEY_D
                        RIGHT
                )
                (KEY_A
                        LEFT
                )
                (else
                        CENTER
                )
        )
)