STL之容器适配器queue类-急流勇进篇(五)

#include <iostream>
#include <queue>
#include <string>

using namespace std;

int main()
{
    queue<string> qu;

    //在队列的末尾添加元素
    qu.push("string1");
    qu.push("string2");
    qu.push("string3");
    qu.push("string4");

    //返回队列的第一个元素
    string str=qu.front();
    cout<<"The first string of queue qu:"<<str<<endl;

/*___________________________________________________________________________________
执行结果：
The first string of queue qu:string1
____________________________________________________________________________________*/

    //删除第一个元素
    qu.pop();
    str=qu.front();
    cout<<"After pop,the first string of queue is:"<<str<<endl;
    
/*___________________________________________________________________________________
执行结果：
After pop,the first string of queue is:string2
____________________________________________________________________________________*/

//返回队列的最后一个元素
str=qu.back();
cout<<"The last string of queue qu:"<<str<<endl;
/*___________________________________________________________________________________
执行结果：
 The last string of queue qu:string4
____________________________________________________________________________________*/

//返回队列元素的个数
int num=qu.size();
cout<<"The total number of queue qu is:"<<num<<endl;

/*___________________________________________________________________________________
执行结果：
 The total number of queue qu is:3
____________________________________________________________________________________*/

//判断队列是否为空
cout << "Is queue qu empty? " << boolalpha << qu.empty() << endl;
/*___________________________________________________________________________________
执行结果：
  Is queue qu empty? false
____________________________________________________________________________________*/


}