OC预处理程序

//
//  Fraction.h
//  OC12预处理程序
//
//  Created by Zoujie on 15/9/17.
//  Copyright (c) 2015年 Zoujie. All rights reserved.
//

//一般预定义常量的替换
#define kTURE 1
#define kFALSE 0
#define PI 3.141592
#define MAXIMUM_DATA_VALUES 1000

//更高级的预定义
#define TWO_PI 2.0 * 3.141592654
#define AND &&
#define OR ||
#define EQUALS ==
#define TWO_PI_Define 2.0 * PI
//带参数
#define IS_LEAP_YEAR(y) y%4 == 0 && y%100 !=0  || y%400==0
#define SQUARE(x) x * x //运算错误 x代表表达式: x = y + 1
#define SQUARE_TURE(x) ((x)*(x))

#define MakeFract(x,y) ([[Fraction alloc]initWith: x over :y]) //?
#define MAX_TWO_NUMBER(a,b)  (((a)>(b)) ? (a):(b)) //判断两参数大小

#define IPAD //申明

#import <Foundation/Foundation.h>//<>系统头文件

@interface Fraction : NSObject
-(void)defineProduct;
-(double) area;
-(double) circumference;
-(void)initWith:x over:y;
@end

//
//  Fraction.m
//  OC12预处理程序
//
//  Created by Zoujie on 15/9/17.
//  Copyright (c) 2015年 Zoujie. All rights reserved.
//

#import "Fraction.h"

@implementation Fraction
{
int radius ;//半径
}
-(void)defineProduct
{
int gameover = kFALSE;
if (gameover == kFALSE)
{
gameover = kTURE;

}

if (gameover >0 AND (gameover <= 1)){}
if (gameover >0 OR (gameover <= 1)){}

}

-(double) area
{
radius = 10;
return PI * radius * radius;
}

-(double) circumference
{

return 2.0 * PI * radius;
return TWO_PI * radius;
return TWO_PI_Define * radius;
}

-(void)initWith:(id)x over:(id)y
{

return ;
}

@end

//
//  main.m
//  OC12预处理程序
//
//  Created by Zoujie on 15/9/17.
//  Copyright (c) 2015年 Zoujie. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "Fraction.h"
#import <limits.h>
#import <float.h>

int main(int argc, const char * argv[]) {
@autoreleasepool {

if  (IS_LEAP_YEAR(2000))
{
NSLog(@"判断闰年");
}

NSLog(@"%d",MAX_TWO_NUMBER(100, 99));
}
return 0;
}

#pragma mark 条件编译

#ifdef IPAD //IPAD 申明就可以
#define kImageFile @"bardHD.png"
#else
# define kImageFile @"barn.png"
#endif

//用于注释
#if 0
#endif

#undef 语句
//使一些已经地宫一的名称成为未定义的
#undef IPAD  //消除IPAD  #ifdef IPAD #if defined(IPAD) 判断都为FALSE