-)a)( 0 Posted August 23, 2003 Hi, i don't it this bug was mentioned in this forums in the past, so i will share my knowledge. If you use the set-command on an array called "A" and you has an array "B" with exact the same content, both arrays will be changed. This bug appears even when the second array is in a local scope (with the "_" at the beginning). Does anyone can confirm this bug? [i hope my OFP is ok ;) !] Because the new patch was just released, so i don't have hopes that this bug will be fixed ever. Greetz Dax Share this post Link to post Share on other sites
bn880 5 Posted August 23, 2003 Yes this is a known issue by quite a few people. When you do arr1 = arr2 and the arrays are multidimensional, arr2 is basically a reference like arr1 to the same elements. That is also why you can not do arr1=[[1,2],[3,4]] arr1=arr1-[1,2] because [1,2] is basically a reference which you have no access to other than with set. Basically you are working with pointers in OFP. Pointers that are automatically dereferenced by OFP commands. Share this post Link to post Share on other sites
suma 8 Posted August 24, 2003 This is intended behaviour, see Command Refrerence, Scripting topics: Array assignment Assignment used on arrays assigns only pointer to the same array to the target variable. When b is an array, after executing a = b both a and b represent the same array. When b is changed, a is changed as well. One particular situation that can lead to this behaviour is aList = list sensor_name. You can force creating a copy of array by using unary operator +Array Share this post Link to post Share on other sites
-)a)( 0 Posted August 24, 2003 Thank you very much for you replies, and sorry for not reading the Comref exact, next time i should go a little bit deeper into the details. Share this post Link to post Share on other sites
bn880 5 Posted August 24, 2003 Don't go yet, there is something else you should know: the unary operator + will copy the array, multidimensional or not, but if your array has pointers inside of it, it will copy the pointers to those arrays (as it makes identical copy). So this will be dangerous for functions that return arrays within arrays like this; arr1 = [1,2,3] arr2 = [arr1,4] arr3 = +arr2 arr1 set [2,5] NOW arr1 > [1,2,5] arr2 > [arr1,4] arr3 > [arr1,4] dereference arr2 and arr3 (as in sidechat or access) arr2 > [[1,2,5],4] arr3 > [[1,2,5],4] another problem would be if your function modifies arr3 select 0 select X, it will actually modify the array arr1 in parent function and thus arr2 in parent function would appear to change as well. (since it has pointer to arr1). Best thing to do is: arr1 = [1,2,3] arr2 = [+arr1,4] arr3 = +arr2 Share this post Link to post Share on other sites
-)a)( 0 Posted August 24, 2003 Thank you, it seems to me that you had much fun with the arrays during making CoC. Share this post Link to post Share on other sites
bn880 5 Posted August 24, 2003 That's exactly it, we had loads of fun. We still do. Share this post Link to post Share on other sites
