#include <iostream>

#include <string.h>

using namespace std;

int my_len(const char *str)

{

	int len = 0;

//	while (*str != '\0')

//	{

//		++len;

//		++str;

//	}

	while (*(str++) != '\0')

	{

		++len;

	}

	return len;

}

void my_cpy(char *dst,const char *src)

{

	while (*src != '\0')

	{

		*dst = *src;

		++dst;

		++src;

	}

}

int main()

{

	char str1[] = "abc";//后面自己主动加上'\0'

	char str2[] = { 'a', 'b', 'c' };//后面不会自己主动加上个'\0'，作为字符串会一直找到'\0'标志

	char str3[] = { 'a', 'b', 'c' ,'\0'};

	char str4[10] = "abc";

	//              4                      3                      4                      10

	cout << sizeof(str1) << "," << sizeof(str2) << "," << sizeof(str3) << "," << sizeof(str4) << endl;

	//              3                      15                      3                      3

	cout << strlen(str1) << "," << strlen(str2) << "," << strlen(str3) << "," << strlen(str4) << endl;

	cout << my_len(str1) << "," << my_len(str2) << "," << my_len(str3) << "," << my_len(str4) << endl;

	//       abc       abc烫烫烫烫蘟bc    abc            abc

	cout << str1 << "," << str2 << "," << str3 << "," << str4 << endl;

	//字符串赋值

	//str1 = str2;// 错误。数组名是地址常量

	//str1 = "hello";// 错误。数组名是地址常量

	strcpy(str4,str1);

	//strcmp(str1,str2);字符串比較

	//strcat(str3,str2);字符串拼接，必须推断空间是否够

	//字符串切割

	char str[] = "this is a test";

	char *token = strtok(str, " ");

	while (token != NULL)

	{

		cout << token << endl;

		token = strtok(NULL," ");

	}

	return 0;

}

c++风格字符串

#include <iostream>

#include <string>

using namespace std;

int main()

{

	string str1 = "hello";

	string str2 = "abc";

	string str3 = "abc";

	//拷贝赋值

	str3 = str1;

	cout << str1 << "," << str3 << endl;

	//获取长度

	cout << str1.length() << endl;

	//字符串的比較

	str1.compare(str3);

	//字符串拼接

	str3 += str2;

	//字符串切割

	string str4 = "this is a test";

	//转换为c风格的string

	//char *token = strtok((char *)str4.c_str(), " ");//强制类型转换

	char *token = strtok(const_cast<char *>(str4.c_str()), " ");

	while (token != NULL)

	{

		cout << token << endl;

		token = strtok(NULL, " ");

	}

	//遍历字符串(string::size_type i = 0; i < str1.length();i++)

	for (string::size_type i = 0; i < str1.length(); i++)

	{

		cout << str1[i] << "-" ;

	}

	cout << endl;

	for (string::size_type i = 0; i < str1.length(); i++)

	{

		cout << str1.at(i) << "-";

	}

	cout << endl;

	for (string::iterator itr = str1.begin(); itr != str1.end();++itr)

	{

		cout << *itr << "-";

	}

	cout << endl;

	int cnt = 0;

	while (cnt < 50)

	{

		if (str1.size() == str1.capacity())

		{

			//cout << "hhh";

		}

		str1.push_back('*');

		cnt++;

		//cout << str1.size() << "," << str1.capacity() << endl;

	}

	str1.clear();

	if (str1.empty())

	{

		cout << "str1.empty";

	}

	return 0;

}