Functions Questions

• C syntax rule: “A function cannot be defined inside another function.” Decide whether this statement is correct or incorrect (standard ISO C, not extensions).
• Modern C (C99 and later): “If the return type for a function is not specified, it defaults to int.” Decide whether this statement is correct or incorrect.
• C control flow: “A function may contain multiple return statements that return different values along different paths.” Decide whether this statement is correct or incorrect (assume a non-void function).
• Parameter passing in C: “Functions can be called either by value or by reference.” Decide whether this statement is correct or incorrect.
• Linking and symbol visibility: “Names of functions in two different source files linked into one program must be unique.” Decide whether this statement is correct or incorrect.
• Compiler diagnostics: “If a function contains two return statements one after another, the compiler will generate warnings.” Decide Yes or No (consider typical conforming compilers).
• C return types: “Functions cannot return a floating-point number.” Decide Yes or No.
• In C programming, is there a fixed maximum number of arguments a function can accept (for example, “at most 12”)? Provide the best general answer for standard-conforming C across common platforms.
• In C, must every function return a value, or are non-returning (void) functions valid? Answer for standard C across common platforms.
• Modern ISO C (C99/C11+): will the following functions compile and work without a prior prototype for f2? int f1(int a, int b) { return ( f2(20) ); } int f2(int a) { return (a*a); } Assume no forward declaration is provided.
• In C, may a function legally contain multiple return statements, or should there never be more than one?
• Algorithmic performance in C: as a general rule, does recursion usually run slower than equivalent loops due to call overhead and stack usage?
• Recursion and system resources: can too many recursive calls in a C program cause a stack overflow on typical systems?
• C++ name clashes and multiple inheritance: will this program compile, and what does the qualified call print? #include static int Result; class India{ public: void Change(int x=10,int y=20,int z=30){ cout << x+y+z; } void Display(int x=40, float y=50.00){ Result = x % x; cout << Result; } }; class CuriousTab{ int x,y; public: void Change(int x,int y=50){ cout << x+y; } }; class CuriousTab: public India, public CuriousTab{ public: void Display(int x=10,int xx=100,int xxx=1000){ Result = x + xx % x * x; cout << Result; } }; int main(){ CuriousTab objCuriousTab; objCuriousTab.India::Display(10, 20.00); }
• C++ defaults and pre-decrement with mixed integer/float args: evaluate the expression a % 20 + c * --b for the provided call. #include class CuriousTabSample{ public: int a; float b; void CuriousTabFunction(int a, float b, float c=100.0f){ cout << a % 20 + c * --b; } }; int main(){ CuriousTabSample obj; obj.CuriousTabFunction(20, 2.000000f, 5.0f); }
• C++ swapping via pointers to members in two different objects: after Exchange(&objA.x, &objB.y), what prints? #include class CuriousTab{ public: int x, y; CuriousTab(int xx=10,int yy=20){ x=xx; y=yy; } void Exchange(int*, int*); }; void CuriousTab::Exchange(int *x, int *y){ int t; t=*x; *x=*y; *y=t; } int main(){ CuriousTab objA(30,40), objB(50); objA.Exchange(&objA.x, &objB.y); cout << objA.x << " " << objB.y << endl; }
• C++ pointer size vs. string contents: what does this program actually print when taking sizeof on a char* variable (legacy headers)? #include #include #include class CuriousTabString{ char txtName[20]; public: CuriousTabString(char txtTemp=NULL){ if(txtTemp!=NULL) strcpy(txtName, txtTemp); } void Display(){ cout << txtName; } }; int main(){ char txtName=(char)malloc(10); strcpy(txtName, "CuriousTab"); txtName = 48; // overwrite first char CuriousTabString objTemp(txtName); cout << sizeof(txtName); }
• C++ references and default constructor print: what will this program output when passing pre-incremented and pre-decremented references to the constructor? #include class CuriousTab { int x, y, z; public: CuriousTab(int x = 100, int y = 30, int z = 0) { this->x = x; this->y = y; this->z = z; Display(); } void Display() { cout << x << " " << y << " " << z; } }; int main() { int a = 0, b = 1, c = 2; int &x = ++a; // a becomes 1, x binds to a int &y = --b; // b becomes 0, y binds to b int z = c + b - -c; // z = c + b + c = 4 CuriousTab objCuriousTab(x, y, z); return 0; }
• C++ recursion with a static accumulator and member mutation: what does this program print? #include class TestDrive { int x; public: TestDrive(int xx) { x = xx; } int DriveIt(void); }; int TestDrive::DriveIt(void) { static int value = 0; // accumulates across recursion int m; m = x % 2; // current parity bit x = x / 2; // shift right by 1 (integer divide) if ((x / 2)) DriveIt(); value = value + m * 10; return value; } int main() { TestDrive TD(1234); cout << TD.DriveIt() * 10 << endl; return 0; }
• C++ default arguments and integer truncation: what is printed by this program? #include int main() { float Amount; float Calculate(float P = 5.0, int N = 2, float R = 2.0); Amount = Calculate(); cout << Amount << endl; return 0; } float Calculate(float P, int N, float R) { int Year = 1; float Sum = 1; Sum = Sum * (1 + P * ++N * R); Year = (int)(Year + Sum); return Year; }