Hi Friends, I have a code line having two "Do" loops, one within other. In certain situation arising within inner loop, I want the inner as well as outer "Do" loops to break simultaneously. How to achieve it ? The Break[] function I tried only breaks the inner loop, not the outer one. Here is a simplified example. R[0] = 0; dsc = {-6, -5, -4, -3, -2, -1, 0, 1, 2}; X = Reap[X = 1; Do[Do[If[dsc[[k]] < 0, R[m] = R[m - 1] + 1; Sow[R[m]]; Sow[{m, k}]; X = 1 + k; If[R[m] != R[m - 1], Break[]], Sow[{m, k}]; Break[]], {k, X, 10}], {m, 1, 8}]][[2]] The o/p of this code is {{1,{1,1},2,{2,2},3,{3,3},4,{4,4},5,{5,5},6,{6,6},{7,7},{8,7}}} Here, basically the inner Do loop breaks as soon as the dsc hits a non-negative number and there is no further advancement of R[m] after the m and k hit the values {6, 6} during two Do loops. What I want to achieve is the breaking of m loop as well once dsc[[k]] hits a positive number. So basically I want to see the o/p {{1, {1, 1}, 2, {2, 2}, 3, {3, 3}, 4, {4, 4}, 5, {5, 5}, 6, {6, 6}} Will appreciate any suggestion on it. Thanks

To be clear, The "done" is arbitrary -- you can return whatever you want or Null. I still do not understand the exact computation but here is a close example. For example, you can determine in advance the sublist of the k loop dscShort = dsc[[1 ;; (Position[dsc, _?NonNegative, 1, 1][[1, 1]] - 1)]] I constructed a shortened version of dsc. Now you can map a function over that to do your second "loop" MapIndexed[(rr[#2[[1]]] = rr[#2[[1]] - 1] + 1) &, dscShort] I used MapIndexed because you want to use the "m" in your definition of R (I use lowercase -- it is always better so you do not step on Mathematica Symbols). Note that I did not use the value of dsc in the definition because you only used "m" in your example but #1 would refer to the dsc value in a more complex function. I do not understand how you intend to use a 2 dimensional dsc but you can easily map the shortening function over a 2-d list for example: multiShort[x_] := Map[#[[1 ;; (Position[#, _?NonNegative, 1, 1][[1, 1]] - 1)]] &, x] multiShort[dsc2D] would give you a list of shortened dsc lists that you can now map over. I hope this helps. Regards, Neil

By the way, what alternative would you suggest instead of "Do", if it does not disturb my rest of the code, may try !! Thanks once again ! Take a look at this post from StackExchange for some alternatives to loops. Actually, `Do` can be a reasonably good option in some cases. It's usually `For` that you want to avoid.

Thanks a lot Neil, appreciate your help. I was trying to "Throw" Break[] from k loop to m loop instead of "done", perhaps the reason why it was not working. The only reason for insisting on "Do" is that I have already invested few months to write this code and would like stick to it. I started with "For", and then had to switch to "Do" after several issues. By the way, what alternative would you suggest instead of "Do", if it does not disturb my rest of the code, may try !! Thanks once again !

[?] Break outer Do loop by an incident in inner Do loop?