c ++向量库

The ways that we are using to copy vectors in C++, are:

我们用于在C ++中复制向量的方法是：

1. Copy one vector's elements to another (Simple approach)

   将一个向量的元素复制到另一个(简单方法)

2. Copy vector by using an assignment operator

   通过使用赋值运算符复制向量

3. Copy vector 1 to vector 2 while declaring vector 2 by passing the first vector as an argument (parameterized constructor)

   通过将第一个向量作为参数传递来声明向量2的同时将向量1复制到向量2(带参数的构造函数)

1)将一个向量的元素复制到另一个(简单方法) (1) Copy one vector’s elements to another (Simple approach))

#include <iostream>
#include <vector>
using namespace std;
int main()
{
//declar and initialize vector 1
vector<int> v1{10,20,30,40,50};
//declare vector2
vector<int> v2;
//copy v2 to v1
for(int i=0; i<v1.size(); i++){
v2.push_back(v1[i]);
}
//printing v1 and v2
cout<<"v1 elements: ";
for(int i=0; i<v1.size(); i++){
cout<<v1[i]<<" ";
}
cout<<endl;
cout<<"v2 elements: ";
for(int i=0; i<v2.size(); i++){
cout<<v2[i]<<" ";
}
cout<<endl;	
return 0;
}

Output

输出量

v1 elements: 10 20 30 40 50
v2 elements: 10 20 30 40 50

2)使用赋值运算符复制向量 (2) Copy vector by using an assignment operator)

Syntax:

句法：

 v2 = v1;

#include <iostream>
#include <vector>
using namespace std;
int main()
{
//declar and initialize vector 1
vector<int> v1{10,20,30,40,50};
//declare vector2
vector<int> v2;
//copying v1 to v2
v2 = v1;
//printing v1 and v2
cout<<"v1 elements: ";
for(int i=0; i<v1.size(); i++){
cout<<v1[i]<<" ";
}
cout<<endl;
cout<<"v2 elements: ";
for(int i=0; i<v2.size(); i++){
cout<<v2[i]<<" ";
}
cout<<endl;	
return 0;
}

Output

输出量

v1 elements: 10 20 30 40 50
v2 elements: 10 20 30 40 50

3)将向量1复制到向量2，同时通过将第一个向量作为参数传递来声明向量2(参数化构造函数) (3) Copy vector 1 to vector 2 while declaring vector 2 by passing the first vector as an argument (parameterized constructor))

Syntax:

句法：

 vector<int> v2(v1);

#include <iostream>
#include <vector>
using namespace std;
int main()
{
//declar and initialize vector 1
vector<int> v1{10,20,30,40,50};
//declare vector2 by copying vector1
vector<int> v2(v1);
//printing v1 and v2
cout<<"v1 elements: ";
for(int i=0; i<v1.size(); i++){
cout<<v1[i]<<" ";
}
cout<<endl;
cout<<"v2 elements: ";
for(int i=0; i<v2.size(); i++){
cout<<v2[i]<<" ";
}
cout<<endl;	
return 0;
}

Output

输出量

v1 elements: 10 20 30 40 50
v2 elements: 10 20 30 40 50

翻译自: https://www.includehelp.com/stl/copy-a-vector-to-another.aspx

c ++向量库