C++ crash course Class 10 practice problems

Pointers The following function is trying to swap the contents of two variables. Why isnt it working? void swap(int &a, int b) { int tmp = a; a = b; b = tmp; }

Strings Write a function which, given a char array and two ints, will return a string * which holds the section between the two ints. Return the null pointer if its not possible. string *substr(char arr[], int start, int stop);

Dynamic Memory Allocation The below is bad practice. Why is that? int *p = new int(5); int j = 7; p = &j;

Pointers This wont compile. Why? double a = 10; int *aptr = &a;

Pointers What is this, and what is its use?

Data Types How is initializing a vector of ints different from initializing a single int?

Data Types Write the following in decimal x21

Files and Unix Whats the difference between > and < on the Unix command line?

Whats the output? int size = 3; int arr[12] = {7, 2, 4}; char name[12] = Jeff Jones; int *iptr; char *cptr; iptr = arr; cout << iptr[1] << and << *iptr << endl; cptr = &name[5]; cout << cptr << endl; cout << *(cptr + 3) << and << *(cptr-4) << endl; cptr ++; cout << name[3] << and << cptr[3] << endl;

Operators What do all of the following do? *itr++; *++itr; (*itr)++;

What does this output? void funct(int a); int main() { int a = 5, *b = &a, c[] = {10, 21, 12}; int *d, *e, f; cout << *b << << *c + 1 << endl; e = b; b = new int; d = new int; *d = 7; *b = 9; *e = 11; cout << *e << *d << a; funct(a); e = b; free(b); cout << *e << f << a; return 0; }

Scope Whats the scope operator (::) doing in these instances? std::cout int Animal_type::avg_age() const What can you do to avoid using the scope operator repeatedly?

Overloading Operators Whats the function prototype to overload the output operator? – return type – function name – parameter list

const What is the purpose of the const keyword? const gets a little tricky with pointers. Give an example.

Loops Write a function to sum even numbers from int a to int b, and return the result.

Reserved Words What are reserved words? Give 3 examples.

Functions Whats the difference between int a, int &a, and int *a in a function parameter list?

? What are these called? What do they do? #include #define #ifndef #endif

Operators What is precedence? What is associativity? Is assignment left or right associative? Is arithmetic left or right associative?

Sorting Sort these using insertion sort, and show all the steps

Sorting Write an insertion sort on a vector of int *.

Classes Whats a constructor? How do you identify one? Write a default constructor for this class: class Mystery { int a; bool b; string s; };

Classes What is the difference between public, private and friend?

Data Types Whats the difference between a literal and a constant?