4.9 Accessing the Characters Within a String
Extracting individual characters from a string is a very common task. It is so easy that HLA doesn't provide any specific procedure or language syntax to accomplish this—you simply use machine instructions to accomplish this. Once you have a pointer to the string data, a simple indexed addressing mode will do the rest of the work for you.
Of course, the most important thing to keep in mind is that strings
are pointers. Therefore, you cannot apply an indexed addressing
mode directly to a string variable and expect to extract characters from the
string. That is, if
s is a string variable,
mov( s[ebx], al ); does not fetch the
character at position EBX in string
s and place it in the AL register. Remember, ...