member initializer list in c 2b 2b

1// Constructor Member Initializer List
2
3#include <iostream>
4
5class Example
6{
7private:
8    int x, y;
9
10public:
11    Example() : x(0), y(0) {}
12    Example(int x1, int y1) : x(x1), y(y1) {}
13    ~Example() {}
14};
15
16int main()
17{
18    Example e;
19}

1struct S {
2    int n;
3    S(int); // constructor declaration
4    S() : n(7) {} // constructor definition.
5                  // ": n(7)" is the initializer list
6};
7
8S::S(int x) : n{x} {} // constructor definition. ": n{x}" is the initializer list
9
10int main() {
11    S s; // calls S::S()
12    S s2(10); // calls S::S(int)
13}

1#include <iostream>
2class Entity {
3private : 
4	std::string m_Name;
5	int m_Score;
6	int x, y, z;
7public:
8	Entity()
9		:m_Name("[Unknown]"),m_Score(0),x(0),y(0),z(0)//initialize in the order of how var are declared
10	{
11	}
12	Entity (const std::string& name) 
13		:m_Name(name)
14	{}
15	const std::string& GetName() const { return m_Name; };
16};
17int main()
18{
19	Entity e1;
20	std::cout << e1.GetName() << std::endl;
21	Entity e2("Caleb");
22	std::cout << e2.GetName() << std::endl;
23	std::cin.get();
24}

1class Something
2{
3private:
4    int m_value1;
5    double m_value2;
6    char m_value3;
7 
8public:
9    Something()
10    {
11        // These are all assignments, not initializations
12        m_value1 = 1;
13        m_value2 = 2.2;
14        m_value3 = 'c';
15    }
16};
17

1class Example {
2public:
3	int m_A, m_B, m_C;
4	Example(int a, int b, int c);
5};
6
7Example::Example(int a, int b, int c):
8	// This is an initializer list
9	m_A(a),
10	m_B(b),
11	m_C(c)
12{ /* Constructor code */ }
13