how can ı write opposite of while loop

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mts 2018-8-18

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评论： Image Analyst 2018-8-19

so i wanted to write loop but my loop need to be opposite of while loop,i mean you know when condition is true while loop keep doing loop and when condition is wrong, loop stop and continue to code. So my loop need to stop when condition is true and my loop need to continue to looping when my condition is wrong.

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Answer 1

Chad Greene 2018-8-18

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Just add a ~ to whatever statement you're using for the while loop. So instead of

while a==b
  ...
end

You could do

while ~(a==b)
  ...
end

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Walter Roberson 2018-8-18

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It would not be uncommon to want to stop a loop as soon as it was detected that the condition was true. For that you could use

while true
   .... some code ...
   if condition_goes_here
     break;
   end
   ... more code ...
end

Image Analyst 2018-8-19

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I'd add a failsafe of the max allowable iterations to be extra robust and prevent infinite loops:

maxIterations = 1000000; % Whatever you think will be way more than you would expect.
loopCounter = 1;
while loopCounter < maxIterations 
    .... some code ...
    if condition_goes_here
        break;
    end
    ... more code ...
    loopCounter = loopCounter  + 1;
end