Call by value
Pascal C/C++
nfunction f(c: char) : integer; forward;
wTRADITIONAL C:
wint f();
wANSI C/C++:
wint f(char c);
w OR
wint f(char);
NOTE: Strictly speaking, no C dialect absolutely requires to declare a function before it is used. If a call to a previously undeclared function is seen, the compiler assumes it is a function returning int and, in the case of ANSI C/C++, makes assumptions about the types of the actual parameters appearing in the call. This serves as an implicit function declaration.