很抽象的问题 : 指针和地址用法

#include <iostream>

int main()
{
// Intrinsic type variables.
char c = 'A';
int i = 123;
long l = 54321;
float f = 3.45;

// Pointers.
char* cp; // to char
int* ip; // to int
long* lp; // to long
float* fp; // to float

// Assign variable addresses to pointers.
cp = &c;
ip = &i;
lp = &l;
fp = &f;

// Reference the variables through the pointers.
std::cout << *cp << std::endl;
std::cout << *ip << std::endl;
std::cout << *lp << std::endl;
std::cout << *fp << std::endl;

return 0;
}

输出是 :
A
123
54321
3.45

我不明白为什麼输出是这样,谁可教教我 ? 十分感谢 ^^