20.C++- "&&&quot…

int func(int i)
{
    cout << "i = " << i  << endl;
    return i ;
}

int main()
{
    int a= (func(0)||func(100));
    cout<<"a = " << a <<endl;
    return 0;
}

i=0
a=0

class Test
{
    int mValue;

public:
    Test(int v)
    {
       mValue = v;
    }

    int value() const
   {
        return mValue;
   }
};

bool operator && (const Test& l, const Test& r)                  //&&重载操作符
{
    return l.value() && r.value();
}

Test func(Test t)
{
     cout << "value()= " << t.value()  << endl;
     return t;
}

int main()
{
　　Test t0(0);
　　Test t1(1);
　　int b= (func(t0)&&func(t1));
　　cout<<"b = " << b <<endl;
}

value()=1             //进入func(t1)
value()=0             //进入func(t0)
b =0

int print(int t)
{
         cout<<t<<endl;
         return t;
}
void func(int a,int b,int c)
{  }

int main()
{
   func(print(1),print(2),print(3));  
   return 0;
}

int i=5,b=4;
int a =(i++,i++,b+4,b=5,i++);         // b=5,且a=(i++)=7,该行运行后,i便等于8
(i,b,a)=10;                                       //a=10,i和b不变

int a[3][3]={ (1,2,3),      
              (4,5,6),
              (7,8,9) };    //只初始化了a[0][0]=3, a[0][1]=6, a[0][2]=9

#include <iostream>
#include <string>

using namespace std;

class Test
{
    int mValue;
public:
    Test(int i)
    {
        mValue = i;
    }

    int value()
    {
        return mValue;
    }

  Test  operator +(int i)                              //重载 + 逗号操作符
  {
      Test ret=this->mValue +i;
      cout<<ret.mValue<<endl;
　　   return ret;
  }

};

Test& operator , (const Test& a, const Test& b) //重载 ,逗号操作符
{
    return const_cast<Test&>(b);
}

int main()
{  
    Test t1(0);
    Test t2(5);
    Test t3=(t1+1,t2+1);return 0;
}

6                         //从最右侧执行t2+1
1                         //最后执行t1+1