Object-C之词典(NSDictionary, NSMutableDictionary)

来源：互联网发布：淘宝相机镜头十大黑店编辑：程序博客网时间：2024/06/04 22:47

//程序启动界面显示之前会调用这个方法//所以将语法代码添加在这里- (void)viewDidLoad {    [super viewDidLoad];    //词典对象 类似java中map集合        //========1.不可变词典========    NSDictionary *dictionary=[ NSDictionary dictionaryWithObjectsAndKeys:@"jack", @"name", @"25",@"age", nil];        //大小    int len = [dictionary count];    NSLog(@"count=%d",len);        //遍历所有key    NSEnumerator *key= [dictionary keyEnumerator];        for (NSObject *obj in key) {        NSLog(@"key=%@",obj);//key=name ; key=age    }        //遍历所有value    NSEnumerator *value=[dictionary objectEnumerator];        for (NSObject *obj in value) {        NSLog(@"value=%@",obj);    }        //通过key找到value    NSObject *obj= [dictionary objectForKey:@"name"];    if (obj != nil) {        NSLog(@"通过KEY找到的value是: %@",obj);    }        //========2.可变词典========    NSMutableDictionary *mutableDictionary=[NSMutableDictionary dictionaryWithCapacity:10];        //设置值    [mutableDictionary setObject:@"jim" forKey:@"name"];    [mutableDictionary setObject:@"28" forKey:@"age"];        //通过key找到value    NSObject *object=[mutableDictionary objectForKey:@"age"];    if(object!=nil){        NSLog(@"通过KEY找到的value是: %@",object);    }       NSArray *arrayKey= [mutableDictionary allKeys];   NSArray *arrayValue = [mutableDictionary allValues];    }

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