C++ vector :: clear

#include <iostream>
#include <vector>

int main() {
    std::vector<int> numbers = {1, 2, 3, 4, 5};

    std::cout << "Before clear: ";
    for (int num : numbers) {
        std::cout << num << " ";
    }
    std::cout << "
";

    // 清除向量中的所有元素
    numbers.clear();

    std::cout << "After clear: ";
    for (int num : numbers) {
        std::cout << num << " ";
    }
    std::cout << "
";

    // 检查向量的大小和容量
    std::cout << "Size: " << numbers.size() << "
";
    std::cout << "Capacity: " << numbers.capacity() << "
";

    return 0;
}

Before clear: 1 2 3 4 5
After clear: 
Size: 0
Capacity: 5