模拟实现strncat

 代码：

#include<stdio.h>
#include<assert.h>
char* my_strncat(char* dest, const char* src, size_t num) {
	assert(dest != NULL && src != NULL);
	char* ret = dest;
	while (num--) {
		*dest++ = *src++;
	}
	return ret;
}
int main() {
	char arr1[20] = "hahaha";
	char arr2[10] = "yyyyyy";
	my_strncat(arr1,arr2,2);
	printf("%s\n", arr1);
	return 0;
}

结果：