if ask='Yes' then say "You answered Yes" else say "You didn't answer Yes"select... when... otherwise... end for selecting from a number of alternatives:
select when a>0 then say 'greater than zero' when a<0 then say 'less than zero' otherwise say 'zero' end select case i+1 when 1 then say 'one' when 1+1 then say 'two' when 3, 4, 5 then say 'many' enddo... end for grouping:
if a>3 then do say 'A is greater than 3; it will be set to zero' a=0 endand loop... end for repetition:
/* repeat 10 times; I changes from 1 to 10 */ loop i=1 to 10 say i end iThe loop instruction can be used to step a variable to some limit, by some increment, for a specified number of iterations, and while or until some condition is satisfied. loop forever is also provided, and loop over can be used to work through a collection of variables.
Loop execution may be modified by leave and iterate instructions that significantly reduce the complexity of many programs.
The select, do, and loop constructs also have the ability to catch exceptions that occur in the body of the construct. All three, too, can specify a finally instruction which introduces instructions which are to be executed when control leaves the construct, regardless of how the construct is ended.
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