I have a while loop in which I have two for loops. I have a condition in the innermost for loop. Whenever that condition is satisfied I want to exit from both the two for loops and continue within the while loop:
while (1)
for x=1:20
for y=1:30
if(condition)
end
end
end
end
Does Matlab have something like a labeled statement in Java, or is there another way to do this?
One ever so slightly more elegant way than Luis Mendo's. ;-)
while (1)
for x=1:20
for y=1:30
quit = (condition);
if quit
break;
end
end
if quit
break;
end
end
end
Only slightly more elegant than A.Donda's answer (avoids testing the condition twice):
while 1
for x=1:20
for y=1:30
quit = 0;
if (condition)
quit = 1;
break;
end
end
if quit
break;
end
end
end
quit...
quit or for the condition (which takes longer), right?ndgrid. There's no need to test quit in every loop iteration, you're already testing for the condition.Here is a very simple answer leveraging the fact that testing numerous simple conditions is nearly free:
while (1)
go = true;
for x=1:20
for y=1:30
if go && condition
go = false;
end
end
end
end
This approach is very simple, easily generalized to any number of loops and avoids the abuse of error handling.
Another possibility, which avoids using two break statements: if you don't do anything in the outer for loop except calling the inner for loop, you can merge them:
[yy xx] = ndgrid(1:20,1:30);
while 1
for n = 1:numel(x)
x = xx(n);
y = yy(n);
if (condition)
break
end
end
end
A bit of abuse, a bit of overkill, but here it is: yet another way
while (1)
try
for x = 1 : 20
for y = 1 : 30
assert(~(condition), 'break')
end
end
catch err
if ~strcmp(err.message, 'break'), rethrow(err), end
end
end
The nice thing about this approach is that it works with an arbitrary number of nested loops, and only evaluates condition once without having to store the result in a variable.
Inspired by tmpearce's comment.
I'm aware of only one quite inelegant way to do this: check the condition twice.
while (1)
for x=1:20
for y=1:30
if (condition)
break;
end
end
if (condition)
break;
end
end
end
immediate exit for both for loops and continue with the remain of while loop.
while (1)
go=1 %
for x=1:20
if go==0;break; %
for y=1:30
if(condition)
go=0;break; %
end
end
end
end
returnwhenever the condition is met