incompatible implicit declaration of built-in function ‘strlen‘

C语言编译出现 incompatible implicit declaration of built-in function ‘strlen’等

C语言 编译时出现错误

warning: incompatible implicit declaration of built-in function ‘malloc’
 warning: incompatible implicit declaration of built-in function ‘bzero’
 warning: incompatible implicit declaration of built-in function ‘strncpy’
 warning: incompatible implicit declaration of built-in function ‘strlen’warning: incompatible implicit declaration of built-in function ‘memcpy’
warning: incompatible implicit declaration of built-in function ‘memset’
解决办法：
        加入头文件即可
#include<stdlib.h>
#include<string.h>