Objective－C（ Foundation架構 一 NSDictionary）

標籤：

NSDictionary

不可變的字典

建立字典的方法

        // 建立字典的方式        NSDictionary *dy = [NSDictionary dictionaryWithObject:@"a"forKey:@"b"];        NSDictionary *dy1 = [NSDictionary dictionaryWithObjectsAndKeys:@"a",@"b",@"c",@"d" ,nil];                // 快速建立字典        // 重複key值，重複的不能儲存到字典中        NSDictionary *dy2 = @{@"we":@"haha", @"we":@"ha"};                NSLog(@"%@",dy);        NSLog(@"%@",dy1);        NSLog(@"%@",dy2);

 擷取字典的長度

        // 擷取字典長度        NSDictionary *dy2 = @{@"we":@"haha", @"w":@"ha"};        NSLog(@"%lu",dy2.count); // 輸出2           // 如果key值重複，長度不計算在內        NSDictionary *dy2 = @{@"we":@"haha", @"we":@"ha"};        NSLog(@"%lu",dy2.count); //輸出1 

字典的遍曆

        NSDictionary *dy1 = [NSDictionary dictionaryWithObjectsAndKeys:@"a",@"b",@"c",@"d" ,nil];                // 快速建立字典        // 重複key值，重複的不能儲存到字典中        NSDictionary *dy2 = @{@"we":@"haha", @"w":@"ha"};        NSLog(@"%lu",dy2.count);                // 字典的遍曆        for (NSString *key in dy2) {            NSLog(@"key = %@, value = %@", key, [dy2 objectForKey:key]);        }        // 枚舉類型遍曆        [dy1 enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {            NSLog(@"key = %@, value = %@", key, obj);        }];

把字典存到檔案中

        // 把字典儲存到檔案中        NSDictionary *dy2 = @{@"we":@"haha", @"w":@"ha"};        BOOL isWrite = [dy2 writeToFile:@"/Users/cloudwalk/Desktop/test.plist" atomically:YES];        if (isWrite) {            NSLog(@"寫入成功");        }

從檔案中讀取字典

        NSDictionary *readDy2 = [NSDictionary dictionaryWithContentsOfFile:@"/Users/cloudwalk/Desktop/test.plist"];        NSLog(@"%@",readDy2);        

通過把數組添加到字典中，構建成數組字典

        NSArray *sdArr = [NSArray arrayWithObjects:@"zaozhuang",@"jinan",nil];        NSArray *jxArr = [NSArray arrayWithObjects:@"jiujiang",@"nanchang",nil];        NSDictionary *citys = [NSDictionary dictionaryWithObjectsAndKeys:sdArr,@"sd",jxArr,@"jx", nil];        NSLog(@"citys = %@",citys);

 

        NSDictionary *citys = [NSDictionary dictionaryWithObjectsAndKeys:sdArr,@"sd",jxArr,@"jx", nil];        NSLog(@"citys = %@",citys);        // 把citys存到檔案中        [citys writeToFile:@"/Users/cloudwalk/Desktop/test1.plist" atomically:YES];

 

Objective－C（ Foundation架構 一 NSDictionary）