15.字符串

字符串翻转

#include "iostream"
using namespace std;

void reverseString(char *str)
{
	if (NULL == str)
	{
		return;
	}

	int len = strlen(str);
	cout << "len====" << len << endl;


#if 0
	int start = 0;
	int end = len - 1;
	while (start < end)
	{
		char temp = str[start];
		str[start] = str[end];
		str[end] = temp;

		++start;
		--end;
	}
#else

	char *pStart = str;
	char *pEnd = str + len - 1;

	while (pStart < pEnd)
	{
		char temp = *pStart;
		*pStart = *pEnd;
		*pEnd = temp;

		++pStart;
		--pEnd;
	}
#endif


}

//2. 字符串反转
void test03()
{
	char p[] = "abc";
	reverseString(p);
	cout << "p====" << p << endl;
}


int main()
{
	test03();

	system("pause");
	return EXIT_SUCCESS;
}

字符串复制

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
#include<stdlib.h>

void test01()
{
	char str1[] = { 'h', 'e', 'l', 'l', 'o' };
	printf("%s\n", str1);
}

void copyString01(char *dst, const char *source)
{
	int len = strlen(source);

	for (int i = 0; i < len; ++i)
	{
		dst[i] = source[i];
	}

	dst[len] = '\0';
}


void copyString02(char *dst, const char *source)
{
	while (*source != '\0')
	{
		*dst = *source;
		++dst;
		++source;
	}

	*dst = '\0';
}

void copyString03(char *dst, const char *source)
{
	if (NULL == dst)
	{
		return;
	}

	if (NULL == source)
	{
		return;
	}

	while (*dst++ = *source++);
}

//1. 字符串拷贝
void test02()
{
	char *source = "hello world!";
	char buf[1024] = {0};
	//copyString01(buf, source);
	//copyString02(buf, source);
	copyString03(buf, source);
	printf("%s\n",buf);

}


void test04()
{
	char *src = "hello world!";
	char *temp = malloc(100);
	char *p = temp;

	while (*p++ = *src++);

	printf("temp = %s\n", temp);
}

int main(){

	test02();


	system("pause");
	return EXIT_SUCCESS;
}