What is the output of the following program?

Question

What is the output of the following program?

#include <iostream>

           using namespace std;

           int computeValue(int);

           int main()

           {

              int x = 2;

              cout << computeValue(x) << endl;

              return 0;

           }

           int computeValue(int num)

           {

              return num + 5;

           }

Summary

1. The given code produces a result of 7.
2. The following code’s input is ‘x,’ which has been assigned an integer of 2, and the integer is sent to a compute Value function.
3. The function compute Value returns the result of adding 5 to the integer supplied to it.
4. The function receives x (which is 2) and adds 5 to it, resulting in ‘x’ being 7 and 7 is returned.
5. The values returned by the function compute Value are printed in the main, resulting in an output of 7 on the console.

Explanation

#include <iostream>
using namespace std;

int computeValue(int);
int main(){
    int x = 2;
    cout << computeValue(x) << endl;
    return 0;
    
}
int computeValue(int num){
    return num +5;
}

Output:

1. The above image depicts the specified code and the result of its execution, which is 7.

2. The first line of code declares the “iostream” header file, which contains the basic c++ function definitions, which are utilized immediately after including this header file.

3. The second line avoids applying the “std::” all the time to the input and output stream objects cin and cout, respectively, by using the namespace std.

4. If the sentence “using namespace std;” is not used, the statements cin and cout should be prefixed with “std::” because they are from the std library. This sentence essentially relocates all functions from the standard library to the namespace.

5. The function header for the function compute Value can be seen in line 4.

6. The main method receives the first control once the code has begun to be compiled.

7. The function compute Value is called from the main method. However, because the function definition is located below main, the program is unaware of the compute Value function, which could lead to an error.

8. As a result, if the function definition comes after the main method, the function header declaration comes before the main method, allowing the program to recognize that there is a function definition with the function mentioned in the header.

9. The basic method definition is found on lines 5 to 10. “int x=2;” is the first statement in the main method. The type int variable ‘x’ is declared and given the value 2. The variable ‘x’ is then supplied to the function compute Value, and the output stream object “cout” is used to print the value returned by the function.

10. The function definition can be found on lines 12 to 15. The variable ‘x’ is supplied to the function compute Value, which has a value of 2, and the value of ‘x’ + 5 is returned, which is

(2 + 5 = 7) 7.

11. As a result, the given program’s output is 7.

Also, read the Given below-defined UML class diagram.