include c:\cxpl\codes;

proc Exch(A, B, S);
char A, B, S;
int  I, T;
for I:= 0 to S-1 do
        [T:= A(I);  A(I):= B(I);  B(I):= T];


real X, Y;
[X:= 3.0;  Y:= 4.0;
Exch(addr X, addr Y, 8);
RlOut(0, X);  RlOut(0, Y);  CrLf(0);
]