Memory leakage caused by String Concatenation In this link, section "Memory, memory, memory" it's been told that doing many String concatenations in sequence, e.g.: using operator+() multiple times, will cause memory fragmentation, which may lead to the fact that total heap not being totally used.

An alternative I'm suggesting is using strcat() with char buffers and not using Strings at all, and then convert from resultant char buffer to String if a String is needed at the end?
Would that be an escape from fragmentation of the heap?

Clarification: I will specify the upper bound of the char buffer beforehand, as if I know the maximum needed/to-be-used size.
If you size the buffer to be able to hold your final string, then yes, that method will avoid the fragmentation caused by the String concatenation function.

Note that String holds the string as a C-style char array internally; it is the concatenation procedure which dynamically allocates and deallocates memory, causing the fragmentation.