C++超详细讲解标准库

#include <stdio.h>
const char endl = '\n';
class Console
{
public:
    Console& operator << (int i)
    {
        printf("%d", i);
        return *this;
    }
    Console& operator << (char c)
    {
        printf("%c", c);
        return *this;
    }  
    Console& operator << (const char* s)
    {
        printf("%s", s);
        return *this;
    }  
    Console& operator << (double d)
    {
        printf("%f", d);
        return *this;
    }         
};
Console cout;
int main()
{
    cout << 1 << endl;
    cout << "AutumnZe" << endl;
    double a = 0.1;
    double b = 0.2;
    cout << a + b << endl;
    return 0;
}

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
using namespace std;
int main()
{
    printf("Hello World\n");
    char *p = (char*)malloc(16);
    strcpy(p, "AutumnZe");
    printf("%s\n", p);
    double a = 3;
    double b = 4;
    double c = sqrt(a * a + b * b);
    printf("c = %f\n", c);
    free(p);
    return 0;
}

#include <iostream>
#include <cmath>
using namespace std;
int main()
{
    cout << "Hello World" << endl;
    double a = 0;
    double b = 0;
    cout << "Input a:";
    cin >> a;
    cout << "Input b:";
    cin >> b;
    double c = sqrt(a * a + b * b);
    cout << "c = " << c << endl;
    return 0;
}