Comparing strings (revisited)

For some time I have been working on a text based database, in which each entry contains one or more lines of data, with the various fields delimited by semicolons, e.g. A;b;20GM;;;;;Restaurant;090508 n;;;Arintji;; a;Federation Square;;; p;9663 9900;;;9663 9901;;info@arintji.com.au; All was going well but recently I decided to allocate every entry a unique identifier, and, in what with hindsight was clearly misguided enthusiasm, decided that each identifier should be a four digit base 36 number (the 20GM in the first line). This did not cause any problems until yesterday, when I tried to load a name beginning with 'R', and got the first name on the list. When I investigated I found that I was searching the array containing the data using: if ($ident == $data[$i]['group']['ident']) { ...... I then found that I was searching for 20E2, but was getting a match on 2000. I tried 'if ((string) $ident == (string) $data[$i]['group']['ident'])', but this still matched. However 'if($ident === ' worked, as did 'if (!strcmp($ident, $data[$i])) {...'. After puzzling about this for a long time, I realised that the comparison process must have been treating the second value as a floating point number, and converting it to integer, or vice versa. (In floating point notation 20E2 = 20*10^^2 = 2000). I had thought that the (string) override meant to treat the actual value as a string, but in this case it must be converting the (assumed) actual value to a string, and then comparing the results. This surprised me considerably as it is clear from the results I achieve in other circumstances that the data is actually stored as a raw string. $data is a variable format array, and when the original data is read each line is exploded into a term of the data array: $data[][] = explode(';',$line[$i]);. If I print the value of the ident (or any other field) it is always shown as the original string, and when I save an updated version of the data, each term of the data array is imploded into a line of the data file in its original format. However if this value were actually converted to a floating point number when it was entered I would have to specify a format before I could write it out again, and as 20E2 is a rather non-standard format it is most unlikely that it would come out as this unaided. Is there any way to specify that each field is always to be treated as a string when I originally explode the input file into the data array? For someone brought up on rigidly defined data types dynamic typing can be very confusing!