objective-c第四章课后练习答案

////  main.m//  DateTypeConvert///*前6道题 #import <Foundation/Foundation.h>@interface Complex : NSObject-(void) setReal:(double)a;-(void) setImaginary:(double)b;-(void) print;//显示a+bi；-(double) real;-(double) imaginary;-(void) seti:(int)i;-(int) it;@end@implementation Complex{    double real;    double imaginary;    int it;}-(void) seti:(int)i{    it=i;}-(void) setReal:(double)a{    real = a;}-(void) setImaginary:(double)b{    imaginary = b;}-(void) print//显示a+bi；{    NSLog(@"a+bi=%f",real+imaginary*it);}-(double) real{    return real;}-(double) imaginary{    return imaginary;}-(int) it{    return it;}@endint main(int argc, const char * argv[]) {    @autoreleasepool {        //85页的练习题;//        int F = 27℃;//        float C =(float)(F-32)/1.8;//        NSLog(@"wendu=%f℃",C);        //        char c,d;//        c = 'd';//        d = c;//        NSLog(@"d=%c",d);        //        float x = 2.55;//        float theresult = 3*x*x*x-5*x*x+6;//        NSLog(@"theresult=%f",theresult);//        //        float a = 3.31e-8+2.01e-7;//        float b =7.16e-6+2.01e-8;//        NSLog(@"is=%.2e",a/b);                Complex *newComplex=[[Complex alloc] init];        [newComplex seti:2];        [newComplex setReal:3];        [newComplex setImaginary:4];        NSLog(@"RESULT IS ");        [newComplex print];    }    return 0;}*/#import <Foundation/Foundation.h>@interface Rectangle:NSObject-(void) setWidth:(int)w;-(void) setHeight:(int)h;-(int) width;-(int) height;-(void) area;-(void) perimeter;@end@implementation Rectangle{    int width;    int height;    //int area;    //int perimeter;}-(void) setWidth:(int)w{    width =w;}-(void) setHeight:(int)h{    height =h;}-(int) width{    return width;}-(int) height{    return height;}-(void) area{    NSLog(@"%i",width*height);}-(void) perimeter{    NSLog(@"%i",(width+height)/2);}@endint main(int argc, const char * argv[]) {    @autoreleasepool {        Rectangle *newRec=[[Rectangle alloc]init];        [newRec setWidth : 2];        [newRec setHeight : 8];        NSLog(@"面积为");        [newRec area];        NSLog(@"周长为");        [newRec perimeter];    }    return 0;}

////  main.m//  86页Calculator计算器////  Created 15/3/31.//  Copyright (c) 2015年  All rights reserved.//#import <Foundation/Foundation.h>@interface Calculator:NSObject//累加方法-(void) setAccumulator:(double) value;-(void) clear;-(double) accumulator;//算术方法-(double) add: (double) value;-(double) subtract: (double) value;-(double) multiply: (double) value;-(double) divide: (double) value;//第9题添加类-(double) changeSign;//改变累加器的正负号-(double) reciprocal;//累加器-(double) xSquared;//累加器的平方//第10 题添加存储功能-(double) memoryClear;//清理内存-(double) memoryStore;//设置内存为累加器-(double) memoryRecall;//设置累加器到内存-(double) memoryAdd:(double) value;//添加值到内存-(double) memorySubtract:(double) value;//与内存的值相减@end@implementation Calculator{    double accumulator;    double memory;}-(void) setAccumulator:(double) value{    accumulator=value;}-(void) clear{    accumulator =0;}-(double) accumulator{    return accumulator;}//算术方法-(double) add: (double) value{    accumulator+=value;    return accumulator;    //NSLog(@"add:%g",accumulator);}-(double) subtract: (double) value{    accumulator-=value;    return accumulator;}-(double) multiply: (double) value{    accumulator *=value;    return accumulator;}-(double) divide: (double) value{    accumulator /=value;    return accumulator;}-(double) changeSign    //改变累加器的正负号{    accumulator = -(accumulator);    return accumulator;}-(double) reciprocal    //累加器{    return accumulator;}-(double) xSquared      //累加器的平方{    accumulator *=accumulator;    return accumulator;}//第10 题添加存储功能-(double) memoryClear   //清理内存{    accumulator=memory;    memory =0.0;    return accumulator;}-(double) memoryStore   //设置内存为累加器{    memory=accumulator;    return accumulator;}-(double) memoryRecall   //设置累加器到内存{    accumulator=memory;    return accumulator;}-(double) memoryAdd:(double) value    //添加值到内存{    memory +=value;    accumulator=memory;    return accumulator;}-(double) memorySubtract:(double) value   //与内存的值相减{    memory -=value;    accumulator=memory;    return accumulator;}@endint main(int argc, const char * argv[]) {    @autoreleasepool {        Calculator *deskCalc=[[Calculator alloc]init];        [deskCalc setAccumulator:100.0];        [deskCalc add:200.0];        [deskCalc divide:15.0];        [deskCalc subtract:10.0];        [deskCalc multiply:5.0];        [deskCalc changeSign];        [deskCalc reciprocal];        [deskCalc xSquared];        [deskCalc memoryClear];        [deskCalc memoryStore];        [deskCalc memoryRecall];        NSLog(@"The result is %g",[deskCalc accumulator]);        NSLog(@"The result is %g",[deskCalc memoryAdd:2.0]);        NSLog(@"The result is %g",[deskCalc memorySubtract:1.0]);    }    return 0;}

新手，编写如有纰漏，敬请指正！谢谢！