In addition to the standard Pascal assignment operator (:=), Free Pascal supports some c-style constructions. All available constructs are listed in table (1.5).
| Assignment | Result |
| a += b | Adds b to a, and stores the result in a. |
| a -= b | Substracts b from a, and stores the result in a. |
| a *= b | Multiplies a with b, and stores the result in a. |
| a /= b | Divides a through b, and stores the result in a. |
For these connstructs to work, you should specify the -Sc command-line switch.
Remark: These constructions are just for typing convenience, they don't generate different code.
Free Pascal also supports typed assignments. This means that an assignment statement has a definite type, and hence can be assigned to another variable. The type of the assignment a:=b is the type of a (or, in this case, of b), and this can be assigned to another variable : c:=a:=b;. To summarize: the construct
a:=b:=c;results in both a and b being assign the value of c, which may be an expression.
For this construct to be allowed, it is necessary to specify the -Sa4 switch on the command line.