Question 16: Predict the output.

Question 16: Predict the output. (Considering int for 4 bytes)

    void display(int data[])
    {
        std::cout<<"\nSize of array when passed as argument is : "<<sizeof(data);
    }

    int main()
    {
        int data[] = { 1, 2, 3, 4, 5, 6};

        std::cout<<"\nSize of array is : "<<sizeof(data);
        printSizeOfArray(data);
        
    }

    

    Options:
    (a) Size of array is : 24
         Size of array when passed as argument is : 4

    (b) Size of array is : 24
         Size of array when passed as argument is : 24

    (c) Compile Time error.

    (d) None of the above.

Show Solution

Solution: a

Explanation : The value will be passed as pointer instead of whole data.

In C and C++ it is NOT possible to pass a complete block of memory by value as a parameter to a function, but we are allowed to pass its address. In practice this has almost the same effect and it is a much faster and more efficient operation.

To be safe, you can pass the array size or put const qualifier before the pointer to make sure the callee won't change it.