The extended syntax (enabled using a {$X+} compiler directive) supports a number of new operations on character pointers.

The plus (+) and minus (-) operators can be used to increment and decrement the offset part of a pointer value.

The minus operator can be used to calculate the distance (difference) between the offset parts of two character pointers.

Assuming that P and Q are values of type PChar and I is a value of type Word, these constructs are allowed:

P + I, I + P

The operations P + I and I + P add I to the address given by P, producing a pointer that points I characters after P.

P - I

The operation P - I subtracts I from the address given by P, producing a pointer that points I characters before P.

P - Q

The operation P - Q computes the distance between Q (the lower address) and P (the higher address), resulting in a value of type Word that gives the number of characters between Q and P.

This operation assumes that P and Q point within the same character array. If the two character pointers point into different character arrays, the result is undefined.