Are statements in a Switch-expression necessary?

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Sam
Sam on 20 Dec 2014
Commented: matt dash on 20 Dec 2014
This is my code:
for welke_pp=1:aantal_pp
switch welke_pp
case 1
case 2
case 3
case 4
case 5
end
...
I started a for-loop for 5 subjects. Then I switch them by case 1,2,3,4 and 5. Because the whole for-loop is completely the same for each subject (except for the selected data), I wonder if 'statements' under each 'case-expression' are really necessary for my program?
  6 Comments
dpb
dpb on 20 Dec 2014
No, but in that case there's no need for the specific case either
matt dash
matt dash on 20 Dec 2014
You seem to be misunderstanding the purpose of a switch statement. If the cases are empty, the entire statement does absolutely nothing. The empty switch statement you have is equivalent to:
if welke_pp==1
elseif welke_pp==2
elseif welke_pp==3
elseif welke_pp==4
elseif welke_pp==5
end
You seem to be implying that you think that the switch statment itself is actually changing welke_pp. It doesn't... that is handled by the for loop. The switch statement only looks at the value of welke_pp and performs an action depending on what value it sees (the cases).

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Answers (1)

Guillaume
Guillaume on 20 Dec 2014
You can have a case without any statement, but there is no point writing that specific case in the first place, unless you also have an otherwise. The otherwise catches all the values that have not been dealt with a particular case. You can also regroup case values together if the statements are the same:
switch welke_pp
case 1 %handle value 1
do_fun;
case {2, 3} %handle value 2 and 3
do_otherfun;
case 4 %handle value 4
%does nothing
otherwise %handle all other values
do_somethingelse;
end

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