I have doubt in the output generated

Answer 1

you are passing x(for a) whose value is 24 and b=42
in function
result=x+y=24+42=66
and then the result variable returns and its value get store in variable result (in main)
result=sum(x); which is as same as result=sum(24);

Answer 2

What’s the function, the expected output, and the actual output?

Answer 3

the second function whose output is 66

Answer 4

What’s the code of the function?

Answer 5

#include <iostream>
using namespace std;

int sum(int a, int b=42) {
int result = a + b;
return (result);
}

int main() {
int x = 24;
int y = 36;

//calling the function with both parameters
int result = sum(x, y);
cout << result << endl;

//calling the function without b
result = sum(x);
cout << result << endl;

return 0;
}