main.m

/* 实现图书管理系统:
 1、使⽤数组管理所有书籍。
 2、数组可以添加、删除。
 3、可以从数组根据书名查找书籍,并修改书籍的价格。
 4、展⽰所有书籍清单(书名)。*/

// 创建 对象

Book *book1 = [Book bookWithBookName:@"YIem" price:20];
Book *book2 = [Book bookWithBookName:@"Bian" price:30];
Book *book3 = [Book bookWithBookName:@"bianyi" price:15];
Book *book4 = [Book bookWithBookName:@"YI" price:35];
Book *book5 = [Book bookWithBookName:@"卞一" price:66];
Book *book6 = [Book bookWithBookName:@"卞" price:23];
// 创建可变数组
NSMutableArray *bookArr = [NSMutableArray array];
// 添加书本
[bookArr addObject:book1];
[bookArr addObject:book2];
[bookArr addObject:book3];
[bookArr addObject:book4];
[bookArr addObject:book5];
[bookArr addObject:book6];
NSLog(@"%@", bookArr);
// 删除书本
[bookArr removeLastObject];
NSLog(@"%@", bookArr);
// 查找书名 修改价格
// 1.遍历数组
for (Book *b in bookArr) {
    //判断书名
    if ([b.bookName isEqualToString:@"YIem"]) {
        // 3.改变价格
        b.price = 100;
    }
}
NSLog(@"%@", bookArr);
// 清单
for (Book *b in bookArr) {
    NSLog(@"%@", b.bookName);
}

Book.h

#import <Foundation/Foundation.h>

@interface Book : NSObject
// 书名
@property (nonatomic, copy) NSString *bookName;
// 价格
@property (nonatomic, assign) CGFloat price;
// 初始化

• (instancetype)initWithBookName:(NSString *)name

                         price:(CGFloat)price;

  // 便利构造器

• (instancetype)bookWithBookName:(NSString *)name

                         price:(CGFloat)price;

  @end

Book.m

@implementation Book

// 初始化

• (instancetype)initWithBookName:(NSString *)name price:(CGFloat)price
  {
  self = [super init];
  if (self) {

  self.bookName = name;
  self.price = price;

  }
  return self;
  }

// 便利构造器

• (instancetype)bookWithBookName:(NSString *)name price:(CGFloat)price
  {
  Book *b = [[Book alloc] initWithBookName:name price:price];
  return b;
  }

// 描述方法

• (NSString *)description
  {
  return [NSString stringWithFormat:@"name: %@, price: %.2f", self.bookName, self.price];
  }

Libaray.h

#import <Foundation/Foundation.h>

@class Book;
@interface Libaray : NSObject
// 书本数组
@property (nonatomic, copy) NSMutableArray *bookArr;
// 添加

• (void)addBook:(Book *)book;
  // 删除
• (void)removeBookArrAtIndexes:(NSIndexSet *)indexes;
  // 修改价格
• (void)changPriceByName:(NSString *)name price:(CGFloat)price;
• (void)printBookList;

@end

Libaray.m

#import "Libaray.h"

import "Book.h"

@implementation Libaray
// 初始化

• (instancetype)init
  {
  self = [super init];
  if (self) {

  self.bookArr = [NSMutableArray array];

  }
  return self;
  }

// 添加

• (void)addBook:(Book *)book
  {

  [self.bookArr addObject:book];

  }

// 删除

• (void)removeBookArrAtIndexes:(NSIndexSet *)indexes
  {

  [self.bookArr removeObjectsAtIndexes:indexes];

  }

// 修改价格

• (void)changPriceByName:(NSString *)name price:(CGFloat)price
  {
  // 遍历数组
  for (Book *b in self.bookArr) {

  // 判断
  if ([b.bookName isEqualToString:name]) {
      // 修改
      b.price = price;
  }

  }
  }

// 清单

• (void)printBookList
  {
  for (Book *b in self.bookArr) {

  NSLog(@"清单: %@", b.bookName);

  }
  }

@end

YIem