error: 'NULL' was not declared in this scope
转自:https://blog.csdn.net/libing_zeng/article/details/55668666编译时出现这个错误:error: ‘NULL’ was not declared in this scope解决方式:在文件开头添加如下代码:#include <stddef.h>或者#include <stdlib.h>或者#incl...