c++中如何初始化vector_C++ vector容器初始化方法大全

std::vector<int> vec;           // 空 vector
std::vector<std::string> strVec; // 空字符串 vector

std::vector<int> vec(5);        // 5 个元素，值为 0
std::vector<double> dvec(10);   // 10 个 0.0

std::vector<int> vec(5, 10);     // 5 个元素，每个都是 10
std::vector<std::string> svec(3, "hello"); // 三个 "hello"

std::vector<int> vec = {1, 2, 3, 4, 5};
std::vector<std::string> names{"Alice", "Bob", "Charlie"};

std::vector<int> vec{1, 2, 3}; // 直接列表初始化

std::vector<int> original{1, 2, 3};
std::vector<int> copy = original; // 或 std::vector<int> copy(original);

std::vector<int> v1{1, 2, 3, 4, 5};
std::vector<int> v2(v1.begin(), v1.begin() + 3); // {1, 2, 3}

int arr[] = {10, 20, 30};
std::vector<int> vec(arr, arr + 3);

std::vector<int> vec;
vec.assign(5, 7);                // 5 个 7
vec.assign({1, 2, 3});           // 赋值为 {1,2,3}

struct Point {
    int x, y;
    Point(int x, int y) : x(x), y(y) {}
};
<p>std::vector<Point> points{{1,2}, {3,4}, {5,6}}; // 需支持列表构造

std::vector<int>* pVec = new std::vector<int>{1, 2, 3};
// ...
delete pVec;