编辑代码

#include <stdio.h>
int main () {
    //2.strncat 用例测试
    int n;
    char dest[20] = "Hello";
 
    char src[10] = "1";
 
    strncat(dest, src, 4);//n=5为src前n个字符
 
    printf("%s\n", dest);
   
	return 0;
	
}