IF test in FOR loop

[Josselin]

is it possible to test a condition (true-false) for each element in a
loop like this :

for user in @users (user.has_role? ('manager'))
.....
end

or shoudl I write an if condition inside the loop :

for user in @users
if (user.has_role? ('manager'))
....
end
end

tfyh

joss

 

[Daniel Schierbeck]

is it possible to test a condition (true-false) for each element in a
loop like this :

for user in @users (user.has_role? ('manager'))
....
end

or shoudl I write an if condition inside the loop :

for user in @users
if (user.has_role? ('manager'))
....
end
end

For starters, I would use #each instead of the `for' magic. Second, if
you only wish to process a sub-group of the items, select those first,
and then iterate over them:

@users.select{|user| user.has_role? 'manager'}.each do |user|
# ...
end

It may not be faster, but I think it's easier to read and understand.
You could also split it up, if you prefer:

managers = @users.select{|user| user.has_role? 'manager'}
managers.each{|manager| ...}


Cheers,
Daniel

 

[Yukihiro Matsumoto]

Hi,

In message "Re: IF test in FOR loop"

|is it possible to test a condition (true-false) for each element in a
|loop like this :
|
|for user in @users (user.has_role? ('manager'))
|....
|end
|
|or shoudl I write an if condition inside the loop :
|
|for user in @users
| if (user.has_role? ('manager'))
| ....
| end
|end

for user in @users
next if user.has_role? ('manager')
....
end

or

@users.select{|user| x.has_role?('manager')}.each do |user|
...
end

or anything you like.

matz.