我迷了，为什头文件中注释处代码中的max,显示未定义呢，而没有注释的max显示定义50成功

//#pragma once
//#ifndef SQL_H_INCLUDED
//#define SQL_H_INCLUDED
//
//#define _CRT_SECURE_NO_WARNINGS
//#define max 50
//typedef struct list
//{
//    int data[max];
//    int length;
//
//}list;
//
//#include<stdlib.h>
//#include<stdio.h>
//#include<stdbool.h>
//#include <string.h>
//#include<assert.h>
//void initialarr(int arr[max]);
//void initial(list* L);
//void bing(list* A, list* B);
//void jiao(list* A, list* B);
//
//#endif 
#pragma once
#ifndef SQL_H_INCLUDED
#define SQL_H_INCLUDED
#define _CRT_SECURE_NO_WARNINGS
#define max 50

typedef struct list {
    int data[max];
    int length;
} list;

void initialarr(int arr[max]);
void initial(list* L);
void bing(list* A, list* B);
void jiao(list* A, list* B);

---

#include <stdio.h>
#include <stdbool.h>
#endif