1、基本概念

2、代码实现

#include<stdio.h>
#include<assert.h>

char* My_strcat(char* destination, char* source)
{
	char* ret = destination;
	assert(destination != NULL);//使用断言函数判断指针是否错误
	assert(source != NULL);//使用断言函数判断指针是否错误
	while (*destination)
	{
		destination++;
	}
	while (*destination++ = *source++)
	{
		;
	}
	return ret;
}

int main()
{
	char arr1[20] = { "hello"};
	char arr2[20] = { "world" };
	My_strcat(arr1, arr2);
	printf("%s\n", arr1);
		return 0;
}

3、输出示例