IOS7：学习笔记2

一、Deck类

.h文件

#import <Foundation/Foundation.h>
#import "Card.h"

@interface Deck : NSObject

//atTop是方法名的一部分
//addCard有两个参数，参数穿插在方法名间
-(void)addCard:(Card *)card atTop:(BOOL)atTop;

//addCard方法的重载，用重载的方式实现可选参数
-(void)addCard:(Card *)card;

-(Card *)drawRandomCard;


@end

.m文件

#import "Deck.h"

@interface Deck()
@property (strong,nonatomic) NSMutableArray *cards; //of Card
@end

@implementation Deck

-(NSMutableArray *)cards
{
    if (!_cards)
    {
        _cards=[[NSMutableArray alloc] init];
    }
    return _cards;
}

-(void)addCard:(Card *)card atTop:(BOOL)atTop
{
    if (atTop) {
        [self.cards insertObject:card atIndex:0];
    }
    else
    {
        [self.cards addObject:card];
    }
}

-(void)addCard:(Card *)card
{
    [self.cards addObject:card];
}

-(Card *)drawRandomCard
{
    Card *randomCard=nil;
    
    if ([self.cards count]) {
        unsigned index=arc4random()%[self.cards count];
        randomCard=self.cards[index];
        [self.cards removeObjectAtIndex:index];
    }
    return randomCard;
}

@end

PlayingCar类：

.h文件：

#import "Card.h"

@interface PlayingCard : Card

@property (strong,nonatomic) NSString *suit;
@property (nonatomic) NSUInteger rank;

//+号代表该方法是一个类方法，意味着将它发送给类，而不是对象的实例
//类方法常被用于两种情况：
//1.创建事物
//2.工具方法
+(NSArray *)validSuits;
+(NSArray *)maxRank;


@end

.m文件：

#import "PlayingCard.h"
@implementation PlayingCard

- (NSString *)contents
{
    //这种方法不好，不被使用
    //return [NSString stringWithFormat:@"%d%@",self.rank,self.suit];
    NSArray *rankStrings=[PlayingCard rankStrings];
    return [rankStrings[self.rank] stringByAppendingString:self.suit];
}

//因为提供了setter和getter，要使用@synthesize
@synthesize suit=_suit;//because we provide setter and getter



-(void)setSuit:(NSString *)suit
{
    if ([[PlayingCard validSuits] containsObject:suit]) {
        _suit = suit;
    }
}

-(NSString *)suit
{
    return _suit?_suit:@"?";
}

+(NSArray *)validSuits
{
    return @[@"♥︎",@"♦︎",@"♠︎",@"♣︎"];
}

+(NSArray *)rankStrings
{
    return @[@"?",@"A",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10",@"J",@"Q",@"K"];
}

@end