Need helps on C++ attach. Thanks Pointers with classes a) A user-defined class n

Question

Need helps on C++ attach. Thanks

Pointers with classes a) A user-defined class named Timer has a constructor that takes two integer parameters to initialize hour and minute data members. Write a single C++ statement to create an object of the Timer class using dynamic memory allocation and assign it to a pointer variable named timePt r. It should call the constructor with two parameters. Use values of 10 and 20 for hour and minute respectively. b) Write the definition for a function named randArray that takes a single integer argument, n, and returns a dynamically allocated array of n pseudo-random integers. You may assume the pseudo-random number generator has been previously declared and seeded, (i.e. you do not need srand(time(0)) or an include.) c) Now write C++ statements to call the randAr ray function to construct a 100 element array, then print the array values to the display (one per line) and delete the dynamically allocated array.

Explanation / Answer

Ok. Lets answer your question part by part.

a) We need to create a dynamically allocated object of Timer class, and assign it to a pointer variable timePtr.
As we are going to create an object of timer class, so timePtr will be a pointer of type timer class. Hence, left side of the statement will be as follows.

Timer* timePtr

Now, to dynamically create an object, we use new operator in C++. And at last, we need to call the constructor to create the object. So, the full statement will be as follows:

                         Timer* timePtr = new Timer (10, 20);

b) We need to write function definition for taking single argument n as input and return a dynamically allocated array of pseudo-random integers. It will be as follows:

int* randArray (int n) {
   int* randomArray = new int[n];   //Allocate n ints and save ptr in randomArray.
   for (int i=0; i<n; i++) {
           randomArray[i]   = rand();    //Initialize elements with pseudo-random values
   }
   return randomArray; //return the address of the first element i.e. starting of array
}

c) Here we need to call the randArray function and print the elements values.

int* randomArray = randArray(100); //call randArray function to get a random array of 100 elements
for (int i=0; i<100; i++) {
   cout << randomArray[i] << endl; //Display the elements, one per line
}
delete[] randomArray; //use array delete i.e. delete[], not just delete to deallocate the array
randomArray = 0; //set randomArray ptr to null, use nullptr if using c++11

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