Tumulus

Switch vs. Select

14 posts in this topic

What are the differences between "Switch...Case...EndCase" and "Select...Case...EndCase"?  They seem to have the same function to me. Are there situations in which one is more beneficial than the other?

 

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Switch is comparing against one expression, and then using the Cases to determine which one matches it. Select is more like a compact form of If/Then and each case can be a totally unrelated test parameter to any other comparison being done.

; Switch example
$a = 5
$x = 3
$b = "Dog"
Switch $a
    Case 5
         ;"do this"
    
    Case 4
        ; "do something else"
    Case Else
        ; "nothing matched so do this"
EndSwitch
Select
    Case $a = 4
        ; "do this"
    Case $x = 2
        ; Do this instead
    Case $b = "Dog"
        ; Do something totally unrelated
    Case Else
        ; Do Nothing
EndSelect

 

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#3 ·  Posted (edited)

Switch allows syntax like this:

Case 1, 3, $x

 

Edited by czardas
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No new info here, but I tend to think of it this way.

A switch statement acts...like a switch....doy....  Think of a multiple state toggle switch; a pickup selector switch on a guitar makes for a decent example.  When the switch is moved, it is evaluated based on the discrete value/condition and outputs as designed/programmed.  

A select statement could be seen as the whole guitar.  If I turn the volume nob, adjust volume output...if I adjust a tuning peg, tighten or loosen string...if I plug in guitar...you get the idea.

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Cool analogy, but I think of Switch as a whole guitar and Select as a whole guitar shop.

Local $vGuitar = 'more expensive model', $vDuffer = 'cheap guitar', $iDollars = Random(100, 140, 1)

Switch $vGuitar
    Case 'more expensive model'
        ; get a good quality guitar case
    Case Else
        Select
            Case $vDuffer = 'cheap guitar' And $iDollars <= 120
                ; check out the more expensive model
            Case Else
                ; pay in installments
        EndSelect
EndSwitch

 

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4 minutes ago, czardas said:

Cool analogy, but I think of Switch as a whole guitar and Select as a whole guitar shop.

Micro vs macro I guess. :)

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#7 ·  Posted (edited)

Thanks! Those are really helpful concepts. So as far as I understand, going with my own little analogy, a select could include a bunch of different spacecraft and according to some criteria choose between them. Then with switch, you could determine different travel times based on the different warp drives for each one. Basically that a select deals with different parameters (rebel, empire, purpose) and switch is used for a single expression (millenium falcon)

Local $vXWing = ;type of drive
Local $vMilleniumFalcon = ;type of drive
Local $vTieFighter = ;type of drive

Local $vMyShip
Local $vRebel = 'no'
Local $vEmpire = 'no'
Local $vPurpose = 'smuggling'

Select
    Case $vRebel = 'destroy death star'
        $vMyShip = $vXWing
    Case $vEmpire = 'yes'
        $vMyShip = $vTieFighter
    Case $vPurpose = 'smuggling'
        $vMyShip = $vMilleniumFalcon
        Switch $vMilleniumFalcon
            Case 'standard' ; = type of drive that $millenium falcon is set equal to when declared 
                ;plan for imperial boarding
            Case 'upgraded'
                ;She can outrun an imperial star destroyer
            Case 'Han Solo custom'
                ;kessel run in 12 parsecs
        EndSwitch
End Select

 

Edited by Tumulus
corrected syntax of code.

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Select is sugar for if...else if...else

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And If...Else...EndIf is the salt for Select...EndSelect :P


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Having different ways to write things often makes the code easier to understand and all methods to simplify syntax should be considered valid.

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#14 ·  Posted

@czardas & @spudw2k Thanks for the correction. I think I fixed the case above by adding an object.

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