c++用数组初始化向量_用C++初始化向量

Output

输出量


1
2
3
4
5


方法2&＃xff1a;借助数组&＃xff08;C &＃43;&＃43; 0x&＃xff09;在C &＃43;&＃43;中初始化Vector (Method 2: Initialize a Vector in C&＃43;&＃43; with the help of an array (C&＃43;&＃43;0x))

If you’re using a C&＃43;&＃43;0x (C&＃43;&＃43;03, C&＃43;&＃43;07, etc) based compiler, you can still achieve the initialization using arrays.

如果您使用的是基于C &＃43;&＃43; 0x &＃xff08;C &＃43;&＃43; 03&＃xff0c;C &＃43;&＃43; 07等&＃xff09;的编译器&＃xff0c;则仍可以使用数组实现初始化。


int tmp[] &＃61; { 1, 2, 3, 4, 5 };
std::vector vec( tmp, tmp &＃43; sizeof(tmp)/sizeof(tmp[0]) );


Test this on a C&＃43;&＃43;0x based compiler, to verify that it works.

在基于C &＃43;&＃43; 0x的编译器上进行测试&＃xff0c;以验证其是否有效。


#include
#include using namespace std;int main() {// Initialize a vector using Arraysint tmp[] &＃61; { 1, 2, 3, 4, 5 };std::vector vec(tmp, tmp &＃43; sizeof(tmp)/sizeof(tmp[0]));// Range based for loops not supported in older compilers!// Nor is auto!for (std::vector::iterator it &＃61; vec.begin(); it !&＃61; vec.end(); &＃43;&＃43;it) {std::cout <<*it <}

If you’re on Linux (g&＃43;&＃43; based compiler), compile and run using:

如果您使用的是Linux&＃xff08;基于g &＃43;&＃43;的编译器&＃xff09;&＃xff0c;请使用以下命令进行编译和运行&＃xff1a;


gcc -o test.out test.cpp -std&＃61;c&＃43;&＃43;0x
./test.out


Output

输出量


1
2
3
4
5

方法3&＃xff1a;使用库&＃xff08;C &＃43;&＃43; 11及更高版本&＃xff09; (Method 3: Using the library (C&＃43;&＃43;11 and above))

We can also use the library to achieve this.

我们还可以使用库来实现此目的。

The namespace has the list_of construct to initialize vectors.

名称空间具有用于初始化向量的list_of构造。


#include // Initialize a vector of {1, 2, 3, 4, 5}
std::vector vec &＃61; boost::assign::list_of(1)(2)(3)(4)(5);

We can also use the overloaded &＃43; operator to declare a vector and add elements.

我们还可以使用重载的&＃43;运算符声明一个向量并添加元素。


// Courtesy: https://stackoverflow.com/a/2236233#include // Declare a vector
std::vector vec;// Add elements to it
vec &＃43;&＃61; 1, 2, 3, 4, 5;


However, this type of operator overloading is not advisable, as it can be confusing for many readers, as a person reading this code may also think that the first element will add to 1, the second element adding to 2, etc.

但是&＃xff0c;这种类型的运算符重载是不可取的 &＃xff0c;因为它可能会使许多读者感到困惑&＃xff0c;因为阅读此代码的人可能还会认为第一个元素将加1&＃xff0c;第二个元素加2&＃xff0c;依此类推。

结论 (Conclusion)

In this article, we learned how we could initialize a vector in the C&＃43;&＃43; language in different ways.

在本文中&＃xff0c;我们学习了如何以不同的方式用C &＃43;&＃43;语言初始化向量。

参考资料 (References)

• StackOverflow Question on initializing vectors
  关于初始化向量的StackOverflow问题
• JournalDev Article on Initializer Lists
  JournalDev关于初始化程序列表的文章

翻译自: https://www.journaldev.com/37575/initialize-a-vector-in-c-plus-plus

c&＃43;&＃43;用数组初始化向量