UC知道vector.size(),vector.capacity(),sizeof(vector)的区别
来源：百度知道 编辑：UC知道 时间：2024/06/05 19:56:07
问题：vector.size()，vector.capacity()，sizeof(vector)是怎么计算的，结果跟什么有关？
环境：
gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-47)
代码：
#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<list>
#include<functional>
using namespace std;
#define number 33
vector<bool> vbool(number);
vector<int> vint(number);
vector<double> vdouble(number);
vector<string> vstring(number);
int main()
{
cout << "vbool size == " << vbool.size() << endl;
cout << "vint size == " << vint.size() << endl;
cout << "vdouble size == " << vdouble.size() << endl;
cout << "vstring size == " << vstring.size() << endl;
cout << "vbool bytes == &q
环境：
gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-47)
代码：
#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<list>
#include<functional>
using namespace std;
#define number 33
vector<bool> vbool(number);
vector<int> vint(number);
vector<double> vdouble(number);
vector<string> vstring(number);
int main()
{
cout << "vbool size == " << vbool.size() << endl;
cout << "vint size == " << vint.size() << endl;
cout << "vdouble size == " << vdouble.size() << endl;
cout << "vstring size == " << vstring.size() << endl;
cout << "vbool bytes == &q
vector.size()指的是vector的使用大小，比如说10个盒子，用了8个，vector.size()就等于8
vector.capacity()指的是总大小，上一个例子里，vector.capacity()等于10
sizeof(vector)取决于vector里面存放的数据类型，10个bool就是10个字节，计算起来等于vector.capacity()*单个数据类型大小