C++學習筆記（2）

vector的四種遍歷方法測試

//迭代器測試iterator
void myPrint(int a)
{
	cout <<&a<<"	=	" << a << endl;
}

void test6()
{
	vector<int> v;
	v.push_back(11);
	v.push_back(22);
	v.push_back(33);
	v.push_back(44);
	v.push_back(55);
	//方法一
	cout << "---------方法一----------------" << endl;
	vector<int>::iterator begin = v.begin();
	vector<int>::iterator end = v.end();
	while (begin!=end)
	{
		cout <<"begin._Ptr="<<begin._Ptr<<"	*begin=" << *begin << endl;
		begin++;
	}
	cout << "---------方法二----------------" << endl;
	//方法二
	for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
	{
		cout << "it._Ptr=" << it._Ptr << "	*it=" << *it << endl;
		
	}
	cout << "-----------方法三--------------" << endl;
	
	//方法三
	for (size_t i = 0; i < v.size(); i++)
	{
		cout << "&v[i]=" << &v[i] << "	v[i]=" << v[i] << endl;
	}
	cout << "---------方法四----------------" << endl;
	//方法四
	for_each(v.begin(), v.end(), myPrint);


}
 

執行結果

vector測試

//vector測試
void test7()
{
	vector<int>v;
	for (size_t i = 0; i < 100; i++)
	{
		cout << "v.size()=" << v.size() << "		v.capacity()=" << v.capacity() << "		sizeof(v)=" << sizeof(v) << endl;
		
		v.push_back(1);
	}
}

執行結果

迭代器

void test6()
{
	vector<int> v;
	v.push_back(11);
	v.push_back(22);
	v.push_back(33);
	v.push_back(44);
	v.push_back(55);
	vector<int>::iterator begin = v.begin();
	vector<int>::iterator end = v.end();
	while (begin!=end)
	{
		cout <<"begin._Ptr="<<begin._Ptr<<"	*begin=" << *begin << endl;
		begin++;
	}
}
 

執行結果