<C++ Primer_5th>习题_3.16_练习3.16 c++ primer-优快云博客

本文通过示例代码展示了C++中使用std::vector的不同初始化方式，并打印了每个向量的内容与大小。包括默认初始化、指定数量初始化、指定数量及初始值初始化以及列表初始化等多种形式。

#include<iostream>
#include<string>
#include<vector>	

using namespace std;

int main( )
{
	vector<int> v1;
	vector<int> v2(10);
	vector<int> v3(10, 42);
	vector<int> v4{ 10 };
	vector<int> v5{ 10,42 };
	vector<string> v6{ 10 };
	vector<string> v7{ 10,"hi" };

	cout << "v1的元素个数是: " << v1.size() << endl;
	if (v1.size() > 0)
	{
		cout << "v1的元素分别是: " << endl;
		for (auto c : v1)
			cout << c << " ";
		cout << endl;	
	}

	cout << "v2的元素个数是: " << v2.size() << endl;
	if (v2.size() > 0)
	{
		cout << "v2的元素分别是: " << endl;
		for (auto c : v2)
			cout << c << " ";
		cout << endl;
	}

	cout << "v3的元素个数是: " << v3.size() << endl;
	if (v3.size() > 0)
	{
		cout << "v3的元素分别是: " << endl;
		for (auto c : v3)
			cout << c << " ";
		cout << endl;
	}

	cout << "v4的元素个数是: " << v4.size() << endl;
	if (v4.size() > 0)
	{
		cout << "v4的元素分别是: " << endl;
		for (auto c : v4)
			cout << c << " ";
		cout << endl;
	}

	cout << "v5的元素个数是: " << v5.size() << endl;
	if (v5.size() > 0)
	{
		cout << "v5的元素分别是: " << endl;
		for (auto c : v5)
			cout << c << " ";
		cout << endl;
	}

	cout << "v6的元素个数是: " << v6.size() << endl;
	if (v6.size() > 0)
	{
		cout << "v6的元素分别是: " << endl;
		for (auto c : v6)
			cout << c << " ";
		cout << endl;
	}

	cout << "v7的元素个数是: " << v7.size() << endl;
	if (v7.size() > 0)
	{
		cout << "v7的元素分别是: " << endl;
		for (auto c : v7)
			cout << c << " ";
		cout << endl;
	}

	system("pause");
	return 0;
}