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can any one tell how this break function works in this loop??

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can any one tell me how the break functions if there are two if conditions in a for loop ...
if true
% code
end
locs_Qwave=[ 100 150 90 1175 1 50]';
locs_Rwave=[116 170]';
q=0
k=1
for j=k:size(locs_Rwave)
for i=1:numel(locs_Qwave)
if (i== numel(locs_Qwave))
q=[q locs_Qwave(i)];
break;
end
if( locs_Qwave(i)>locs_Rwave(j))
q=[q locs_Qwave(i-1)];
break;
end
end
end

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Accepted Answer

Adam
Adam on 15 Sep 2014
Edited: Adam on 15 Sep 2014
The second if statement is hit at j = 1, i = 2 so locs_Qwave(1) gets appended to q and it breaks out of the loop before the first if statement kicks in at all. Then we get j = 2 and now the second if statement kicks in at i = 4, adding locs_Qwave(3) to q. Again the first condition plays no part because it is not matched before the second condition matches and breaks out of the loop.
The first of condition appears to only be checking what would be the end of the for loop anyway so it will never activate before the final iteration. All it would do on its own is add a value to q after the for loop has ended which you could do without even having a for loop.
So with the other if statement in there too the first clause will only activate if the second clause is never matched.

  3 Comments

Abhishek sadasivan
Abhishek sadasivan on 16 Sep 2014
thanks ,I also thought in the same way ,but in final iteration(in 6th iteration) the first if statement is true and i believe it has to append the final value of locs_Qwave(i).ie 50.so i except an answer of 0,100,90,50..but when i run this code the answer coming to be 0,100,90.. the last 50 is not there .
Adam
Adam on 16 Sep 2014
You never reach the final iteration. j only runs from 1 to 2 so there are only two outer loops, the first breaks at i = 2, the second at i = 4 and that is the end of the for loop. i = 6 is never reached.
You can just add
q=[q locs_Qwave(end)];
after your for loop if you want that to always happen though. Or add locs_Qwave(end) twice if you want it to happen for each j.

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More Answers (1)

Image Analyst
Image Analyst on 15 Sep 2014
It looks like it should function. What's the problem? If either of those two conditions is met, it breaks out of the "i" for loop and continues on with the "j" for loop.

  1 Comment

Abhishek sadasivan
Abhishek sadasivan on 15 Sep 2014
shall you explain how the break function in this problem.when I run this I got q = 0,100 and 90.If it breaks out from first loop during loop execution I think that it has to come as 0 ,50 ..I am not understanding how it became 0,100,90

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