Writing cleaner code without break or continue
Conditionals and loops example from a Well House Consultants training course
More on Conditionals and loops [link]
Source code: whilly Module: U103
The "goto" statment - in languages that still support it - is
regarded with distain by Computer Scientists as it makes for
spaghetti code - hard to follow and going all over the place!
In some ways, loop controls "break" and "continue" ("last", "next"
and "redo" in Perl; "next", "redo", "retry" and "break" in Ruby)
are also forms of the goto. They are not <i>as</i> bad in that
they only jump within a limited area, but on the other hand many
forms don't involve labels so that there's no clue at the
destination point in your code that it's an arrival point.
Having slagged off these statements (and in reallity I'm being
a pedantic computer scientist by doing so - I use them personally
from time to time!) I had better off you the alternative. Written
on yesterday's Lua course as a demonstration - here's a
while loop that has an ugly break in it ...
while 1 do
if j > 20 then break end
j = j + 1
... and here's the alternative using a control variable. ...
running = true
while running do
if j > 20 then
running = false
j = j + 1
That code being longer, but purer and easier to maintain
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