Objective-C 程序设计（第六版）第三章习题答案

1.   不合法：6_05 (不能以数字开头)

                 A$ ($是非法符号).

2.   myBook  (openBook,closeBook,readBook,takeBook,putBook).

3.   [myBook takeBook];

      [myBook openBook];

      [myBook readBook];

      [myBook closeBook];

      [myBook putBook];

4.   [myBoat driver];

      [myMotorcycle driver];

      [myCar driver];

      重叠.

5.   方便，减小内存（我理解的是这样，题目不是太明白）.

6.   了解过程性语言和面向对象语言的优缺点就OK拉.

7.   

//------------interface部分-------------

#import <Foundation/Foundation.h>

@interface XYpoint : NSObject

- (void) setXcoordinate: (int) x;

- (void) setYcoordinate: (int) y;

- (int) xCoordinate;

- (int) yCoordinata;

@end


//-------------implementation部分-------------

#import "XYpoint.h"

@implementation XYpoint
{
    int xCoordinate;
    int yCoordinate;
}

- (void) setXcoordinate: (int) x
{
    xCoordinate = x;
}

- (void) setYcoordinate: (int) y
{
    yCoordinate = y;
}

- (int) xCoordinate
{
    return xCoordinate;
}

- (int) yCoordinata
{
    return yCoordinate;
}

@end


//-------------program部分------------

#import <Foundation/Foundation.h>
//切记要导入类的头文件
#import "XYpoint.h"

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

    @autoreleasepool {
        
        // insert code here...
        XYpoint *newCoordinate = [[XYpoint alloc]init];
        
        [newCoordinate setXcoordinate:12];
        [newCoordinate setYcoordinate:15];
        
        NSLog(@"newCoordinate is (%d,%d)",[newCoordinate xCoordinate], [newCoordinate yCoordinata]);
        
        
    }
    return 0;
}


//输入结果如下：

          2014-09-14 16:34:18.511 prog1[3284:303] newCoordinate is (12,15)

          Program ended with exit code: 0