I have noticed in Progress (10.4) that repeated string concatenation can be very slow. For example in the following code. DEF VAR i AS INT NO-UNDO. DEF VAR c AS LONGCHAR NO-UNDO. DO i = 1 TO 1000000: c = c + STRING(i MOD 10). END. From my experience in Java, I think the problem is that each time we are concatenating, we are copying c which is an O(n) operation, so the whole procedure is O(n^2). Java provides the StringBuilder class to solve this problem. Is my analysis of the problem correct? And if so, is there a solution? Continue reading...