Predict the output of following C++ programs.
1)
#include <iostream> void init( int a=1, int b=2, int c=3); int main() { init(); return 0; } void init( int a=1, int b=2, int c=3) { std::cout << a << ' ' << b << ' ' << c; } |
The above program looks correct at first glance but will fail in compilation. If function uses default arguments then default arguments can’t be written in both function declaration & definition. It should only be in declaration, not in definition.
The following program is now correct.
#include <iostream> void init( int a=1, int b=2, int c=3); int main() { init(); // It is fine return 0; } void init( int a, int b, int c) { std::cout << a << ' ' << b << ' ' << c; } |
2)
#include <iostream> // something looks missing void init( int =1, int =2, int =3); int main() { init(); return 0; } void init( int a, int b, int c) { std::cout << a << ' ' << b << ' ' << c; } |
If you closely observe function prototype then it looks like an error but it isn’t actually. Variable names can be omitted in default arguments.
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