Returns the number of characters in the string in brackets.

Retrieves a substring of the string in the 1st argument, of the length indicated in the 3rd argument and starting at the offset indicated in the 2nd argument.

Errors are issued for out-of-range operations, returning a NULL string instead.

SUBSTR(“HELLO”,5,1) results in “” (past end of string)

SUBSTR(“HELLO”,-1,3) results in “” (invalid starting offset)

SUBSTR(“HELLO”,0,-1) results in “” (invalid number of characters)

If the 2nd string is found inside the 1st string, this function returns the offset of the 1st character of the 1st occurrence of the 2nd string inside the 1st string. This is a case-insensitive function.

Errors result in a NULL string.

Concatenates two strings.

Performs a case-sensitive comparison of two strings.

Returns 0 if they are identical; otherwise, returns the difference in ASCII values of the first unmatched characters in the two strings.

Performs a case-sensitive partial comparison of two strings.

Returns 0 if the two strings up to the Nth character are identical; otherwise, returns the ASCII difference of the first unmatched characters in the two strings.

Performs a case-insensitive comparison of two strings. The comparison is performed between the lower case equivalents of the two strings.

Returns 0 if the two strings are identical; otherwise, returns the ASCII difference of the first unmatched characters in the two strings.

Performs a case-insensitive partial comparison of two strings. The comparison is performed between the lower case equivalents of the two strings.

Returns 0 if the two strings up to the Nth character are identical; otherwise, returns the ASCII difference of the first unmatched characters in the two strings.