String :: lengthInUnits - Gets the number of text elements in the current String object.
According to the coding type of the String object, the functions returns the number of base characters (all 8 bit coding types), of unsigned integers (UTF16) or unsigned long (UTF32). For coding type UTF8 the number of units may differ from the number of code points contained in the String object.
Return value: Maximum size of buffer or string ( int32 )