Question

Consider the following definition of a C++ class that acts like an array with bounds-checking (i.e. ensuring that a valid array index is used each time an array element is referenced).

class c_array { public:

c_array(int s){
size = s;
a = new int[size];

}
int &operator[](int i); int get_size() {

return size; }

  private:
    int size;
    int *a;

};

1- Write the header for the c-array class in a different header file (c_array.h).

2- Complete the definition of the c_array class by defining its operator[] method, but placing the

definition outside of the class. Be sure that operator[] checks that the index is between 0

and size - 1. If not, the operator should throw an exception.

Answer 1

Please find the code below:

c_array.h

#ifndef C_ARRAY_H_

#define C_ARRAY_H_

class c_array {

public:

c_array(int s);

int &operator[](int i);

int get_size() ;

private:

int size;

int *a;

};

#endif /* C_ARRAY_H_ */

c_array.cpp

#include <iostream>

using namespace std;

#include "c_array.h"

c_array::c_array(int s){

size = s;

a = new int[size];

}

int &c_array::operator[](int i){

if(i<0 || i>=size){

throw out_of_range("Invalid index : "+i);

}

return a[i];

}

int c_array::get_size() {

return size;

}

main.cpp

#include <iostream>

#include "c_array.h"

using namespace std;

int main()

{

c_array myArray(5);

int data;

try{

data = myArray[2];

cout<<"Accesing index 2 : ";

cout<<data<<endl;

cout<<"Accesing index 10 : ";

data = myArray[10];

cout<<data;

}catch(exception e){

cout<<e.what();

}

return 0;

}

output: