Is Case Statements useful?

[livingheaven]

I have a question about case statement. During my compsci class, teacher says we have to use case, but is just like if statement, at some point is worst than if statement

Such as

if a > 1 then

end if

to do that in case you have to do

case a of

lable whatever that is bigger than 1 :

end case


is there a true use for case ????

[Insectoid]

Case statements are better for larger conditionals. They're more organized. If you have like 15 different conditions, it's far neater to do case/label than if/elseif.

[livingheaven]

but case statements can't do if something is larger than some thing

for example

case total of

label total >0 and total >2 :

total := 2

end case

[chrisbrown]

They are useful for menus.

For example:

code:

var input : int get input case input of    label 1: put "input=1"    label 2: put "input=2"    label 3: put "input=3"    label: exit end case

is much cleaner than:

code:

if input = 1 then    put "input=1" elsif input = 2 then    put "input=2" elsif input = 3 then    put "input=3" else    exit end if

They are less robust than if statements but their simplicity makes for cleaner code.

[livingheaven]

so you cant do

case a of

label a > 0 : put 1

end case

????

[chrisbrown]

Nope, equivalence only. The compiler/inperpreter looks at the value of the case variable and scans through the labels until it finds one that matches, then executes that instruction. This allows for optimization: since it doesnt have to do any extra calculations, case statements should be slightly faster, though the difference won't be noticeable.

[livingheaven]

ah men....
this means that i have to some thing like this ..

case a of

label 1,2,3,4,5,6,7,8,9 :

end case

...

[Tony]

you could perform the comparison _before_ the case, store result in a boolean variable, and do a case on that temporary result.

Though this might be a trick question that wants you to find and use the default label.

[livingheaven]

ok .. i'll give it a try
BTW thx guys for helping me

[Kharybdis]

Yo, case statements are much better to do menus with (where you have options) than if statements.

[livingheaven]

i know, but teacher force us to use it lol...

[wtd]

When case statements make the code cleaner, they're useful. When they don't... they're not.

[ProgrammingFun]

In the beginning, I loved case statements because of their simplicity...but when I unlocked the full potential of if statements, I moved on .

Anyways, case statements are useful in simple programs whereas if statements (although messy) can be used anywhere.

[livingheaven]

..Found the answer lol =D

thx u guys..
Btw Tony thx for the help
+ bits..