Question

What is the output of the following C++ code?

int* length;
int* width;

length = new int;
*length = 5;
width = length;
length = new int;
*length = 2 * (*width);

cout << *length << " " << *width << " "
     << (*length) * (*width)
     << endl;

Answer 1

Below is the line by line explaination of the above code -

int* length;
int* width;

Two pointer variables with name length and width are declared here

length = new int;

Pointer variable named length is assigned a memory in the program and it is now pointing(referencing) to a memory block which can hold integral value

*length = 5;

Value of 5 is stored at the memory location pointed by length

width = length;

Pointer variable named width is now pointing to the memory location pointed by length

length = new int;

Pointer variable named length is now assigned a new memory location in the program Note that the previous memory block which contains value of 5 is still pointed by width

*length = 2 * (*width);

Value to be stored at memory location pointed by length is will be two times the value at memory location pointed by width that is two times of 5 that is 10

cout << *length << " " << *width << " "
<< (*length) * (*width)
<< endl;

On printing above values output is -

10 5 50

As value at memory location pointed by length is 10,  value at memory location pointed by width is 5 and product of these 2 values is 50

I have tried to explain it in very simple language and I hope that i have answered your question satisfactorily.Leave doubts in comment section if any.