C++ Programming Code Examples
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Derived class call its base constructor
/* Derived class call its base constructor */
#include <iostream>
using namespace std;
class BaseClass {
protected:
int i;
public:
BaseClass(int x) {
i = x;
cout << "Constructing base\n";
}
~BaseClass() {
cout << "Destructing base\n";
}
};
class DerivedClass: public BaseClass {
int j;
public:
DerivedClass(int x, int y): BaseClass(y) {
j = x;
cout << "Constructing DerivedClass\n";
}
~DerivedClass() {
cout << "Destructing DerivedClass\n";
}
void show() {
cout << i << " " << j << endl;
}
};
int main()
{
DerivedClass ob(3, 4);
ob.show();
return 0;
}
A program shall contain a global function named main, which is the designated start of the program in hosted environment. main() function is the entry point of any C++ program. It is the point at which execution of program is started. When a C++ program is executed, the execution control goes directly to the main() function. Every C++ program have a main() function.
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The cout is a predefined object of ostream class. It is connected with the standard output device, which is usually a display screen. The cout is used in conjunction with stream insertion operator (<<) to display the output on a console. On most program environments, the standard output by default is the screen, and the C++ stream object defined to access it is cout. The "c" in cout refers to "character" and "out" means "output". Hence cout means "character output". The cout object is used along with the insertion operator << in order to display a stream of characters.
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