vector向量push_back()函数运用实例

push_back函数

语法:

1	void push_back(const value_type& __x);

push_back() 在Vector最后添加一个元素

源代码

// [23.2.4.3] modifiers

/**

* @brief Add data to the end of the %vector.

* @param x Data to be added.

* This is a typical stack operation. The function creates an

* element at the end of the %vector and assigns the given data

* to it. Due to the nature of a %vector this operation can be

* done in constant time if the %vector has preallocated space

* available.

void

push_back(const value_type& __x)

{

if (this->_M_impl._M_finish != this->_M_impl._M_end_of_storage)

{

std::_Construct(this->_M_impl._M_finish, __x);

++this->_M_impl._M_finish;

}

else

_M_insert_aux(end(), __x);

}

测试代码

// 梁笔记

// https://zouzhongliang.com

#include <iostream>

#include <vector>

using namespace std;

int main()

{

vector<int> v1;

vector<int> v2(10, 2);

v1.push_back(1);

v1.push_back(2);

v1.push_back(3);

v1.push_back(4);

v1.push_back(5);

for(int i=0;i<v1.size();i++)

cout<<v1[i]<<",";

cout<<endl;

}

测试结果：

1	1,2,3,4,5,