Govt. Exams
Entrance Exams
int counter = 0;
void increment() { static int count = 0; count++; counter++; }
main() { increment(); increment(); printf("%d %d", count, counter); }
The static variable 'count' is local to increment() and inaccessible from main(). Trying to print 'count' causes compilation error: undefined identifier.
Variadic functions use ... syntax, and at least one named parameter must precede it. Option A is correct; Option B violates requirement of at least one named parameter.
Both approaches are valid in C: returning a struct with multiple fields or using pointers as output parameters. Using globals is possible but not recommended.
Array names decay to pointers in function calls. The parameter arr receives the address of the first element, so modifications affect the original array.
Inline functions request the compiler to replace function calls with actual function code, eliminating call overhead. However, compiler may ignore inline suggestion.
Function pointers are powerful features enabling dynamic function selection at runtime, crucial for callbacks, function arrays, and design patterns like strategy pattern.
The parentheses around (*ptr) indicate ptr is a pointer. The remaining (int, int) shows it points to a function taking two int arguments and returning int.
C supports call by value (default) and call by reference (using pointers). Call by value passes a copy; call by reference passes the address allowing modifications to original.
The cdecl (C declaration) calling convention is the standard in C, pushing parameters onto the stack from right to left, with the caller responsible for stack cleanup.
Static variables inside a function have local scope but static storage duration, meaning they retain their value between function calls and are initialized only once.
