IOS开发之旅-IOS常用数据结构NSArray、NSMutableArray、NSDictionary、NSMutableDictionary介绍
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NSArray
- NSArray基本用法
void arrayTest1() { //数组初始化最后必须以nil结尾，表示数组元素结束 NSArray *array1 = [[NSArray alloc]initWithObjects:@"item0",@"item1",@"item2",@"item3",@"item4",nil]; NSLog(@"%@",array1); /*( item1, item2, item3, item4 )*/ //获取数组元素个数 NSLog(@"array count : %ld",array1.count); /*array count : 4*/ //获取特定所以元素 NSLog(@"array[1] = %@",array1[1]); /* array[1] = item1 */ NSLog(@"array[1] = %@",[array1 objectAtIndex:(NSInteger)1]); /* array[1] = item1 */ NSLog(@"firstObject = %@",array1.firstObject); //获取第一个元素 /* firstObject = item1 */ NSLog(@"lastObject = %@",array1.lastObject); //获取最后一个元素 /* lastObject = item4 */ //拼接数组 NSLog(@"%@",[array1 componentsJoinedByString:@","]); /* item0,item1,item2,item3,item4 */ //查找元素的索引，如果包含特定元素，返回具体索引，否则返回：9223372036854775807 NSLog(@"%ld",[array1 indexOfObject:@"item11"]); //是否包含特定元素 NSLog(@"%i", [array1 containsObject:@"item1"] == TRUE ? 1 : 0); /* 1 */ NSArray *subArray = [array1 subarrayWithRange:NSMakeRange(1, 2)]; NSLog(@"%@",subArray); /* ( item1, item2 ) */ //保存数组元素到本地文件，以xml格式序列化存储 [array1 writeToFile:@"/Users/new/Desktop/array.txt" atomically:YES]; /* <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <array> <string>item0</string> <string>item1</string> <string>item2</string> <string>item3</string> <string>item4</string> </array> </plist> */ //读取本地文件，反序列化为数组 NSArray *array2 = [[NSArray alloc]initWithContentsOfFile:@"/Users/new/Desktop/array.txt"]; NSLog(@"%@",array2); /* ( item0, item1, item2, item3, item4 ) */ //判断数组元素是否相等 BOOL result = [array1 isEqualToArray:@[@"item0",@"item1",@"item2"]]; NSLog(@"%@",result); /* 0 */
}
- NSArray遍历
void arrayTest2() { NSArray *array1 = [[NSArray alloc]initWithObjects:@"item0",@"item1",@"item2",@"item3",@"item4",nil]; //遍历方法1 for (int index = 0; index < array1.count; index++) { NSLog(@"%@",array1[index]); } /* item0 item1 item2 item3 item4 */ //遍历方法2 for (NSString *item in array1) { NSLog(@"%@",item); } /* item0 item1 item2 item3 item4 */ //遍历方法3 //NSEnumerator *enumerator = [array1 reverseObjectEnumerator]; //逆向遍历 NSEnumerator *enumerator = [array1 objectEnumerator]; //正向遍历 NSString *item = nil; while (item = [enumerator nextObject]) { NSLog(@"%@",item); } /* item0 item1 item2 item3 item4 */ //遍历方法4 [array1 enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) { NSLog(@"%ld = %@",idx,obj); }]; /* 0 = item0 1 = item1 2 = item2 3 = item3 4 = item4 */ }
- NSArray排序
void arrayTest3() { //排序方法1，普通比较器 NSArray *array1 = @[@"1",@"21",@"11",@"5",@"51",@"3"]; NSArray *array2 = [array1 sortedArrayUsingSelector:@selector(compare:)]; NSLog(@"%@",array2); /* ( 1, 11, 21, 3, 5, 51 ) */ //排序方法2，代码块 NSArray *array3 = [array1 sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) { return [obj1 compare:obj2]; }]; NSLog(@"%@",array3); /* ( 1, 11, 21, 3, 5, 51 ) */ //排序方法3，自定义排序描述符 NSArray *originalArray = @[ @{@"page_no":@"27",@"age":@24}, @{@"page_no":@"1", @"age":@23}, @{@"page_no":@"1", @"age":@21}, @{@"page_no":@"1", @"age":@25}, @{@"page_no":@"1", @"age":@15}, @{@"page_no":@"12",@"age":@19}, @{@"page_no":@"23",@"age":@29}, @{@"page_no":@"3", @"age":@22}, @{@"page_no":@"2", @"age":@30}, @{@"page_no":@"17",@"age":@33} ]; NSSortDescriptor *alphaNumSD = [NSSortDescriptor sortDescriptorWithKey:@"page_no" ascending:YES comparator:^NSComparisonResult(NSString *string1, NSString *string2) { return [string1 compare:string2 options:NSNumericSearch]; }]; NSSortDescriptor *dataNumSD = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:YES comparator:^NSComparisonResult(id data1, id data2) { return [data1 compare:data2]; }]; NSArray *sortedArray = [originalArray sortedArrayUsingDescriptors:@[alphaNumSD,dataNumSD]]; NSLog(@"%@",sortedArray); /* ( { age = 15; "page_no" = 1; }, { age = 21; "page_no" = 1; }, { age = 23; "page_no" = 1; }, { age = 25; "page_no" = 1; }, { age = 30; "page_no" = 2; }, { age = 22; "page_no" = 3; }, { age = 19; "page_no" = 12; }, { age = 33; "page_no" = 17; }, { age = 29; "page_no" = 23; }, { age = 24; "page_no" = 27; } ) */ //排序方法4，自定义比较方法 Person *person1 = [[Person alloc]initWithFirstName:@"hello" lastName:@"world" age:35]; Person *person2 = [[Person alloc]initWithFirstName:@"abc" lastName:@"def" age:25]; Person *person3 = [[Person alloc]initWithFirstName:@"cal" lastName:@"kdl" age:22]; NSArray *personArray = @[person1,person2,person3]; NSArray *tempArray = [personArray sortedArrayUsingSelector:@selector(comparePeople:)]; NSLog(@"%@",tempArray); /* ( " firstName: abc,lastName:def,age:25", " firstName: cal,lastName:kdl,age:22", " firstName: hello,lastName:world,age:35" ) */ }
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NSMutableArray
NSMutableArray继承NSArray,所以NSArray的所有特性NSMutableArray都有，在此基础上,NSMutableArray主要新增了添加、删除、更新、插入等特性，如下代码演示：
void arrrayTest4() { NSMutableArray *mutableArray = [[NSMutableArray alloc]initWithObjects:@"item0",@"item1",@"item2",@"item3",@"item4", nil]; NSLog(@"%@",mutableArray); /* ( item0, item1, item2, item3, item4 ) */ //添加元素 [mutableArray addObject:@"item5"]; NSLog(@"%@",mutableArray); /* ( item0, item1, item2, item3, item4, item5 ) */ //插入元素 [mutableArray insertObject:@"inserted item" atIndex:(NSInteger)1]; NSLog(@"%@",mutableArray); /* ( item0, "inserted item", item1, item2, item3, item4, item5 ) */ //删除元素 [mutableArray removeObject:@"item5"]; NSLog(@"%@",mutableArray); /* ( item0, item1, item2, item3, item4 ) */ //更新元素 [mutableArray replaceObjectAtIndex:(NSInteger)5 withObject:@"replacedItem"]; NSLog(@"%@",mutableArray); /* ( item0, "inserted item", item1, item2, item3, replacedItem ) */ //删除所有元素 [mutableArray removeAllObjects]; NSLog(@"%ld",mutableArray.count); /* 0 */ }
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NSDictionary
- 字典初始化
void arrayTest5() { //字典初始化方式1 NSDictionary *dictionary1 = [[NSDictionary alloc]initWithObjectsAndKeys:@"value0",@"key0", @"value1",@"key1", @"value2",@"key2", @"value3",@"key3", @"value4",@"key4", nil]; NSLog(@"%@",dictionary1); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; } */ //字典初始化方式2 NSArray *valueArray = @[@"value0",@"value1",@"value2",@"value3",@"value4"]; NSArray *keyArray = @[@"key0",@"key1",@"key2",@"key3",@"key4"]; NSDictionary *dictionary2 = [[NSDictionary alloc]initWithObjects:valueArray forKeys:keyArray]; NSLog(@"%@",dictionary2); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; } */ //字典初始化方式3 NSDictionary *dictionary3 = @{ @"key0":@"value0", @"key1":@"value1", @"key2":@"value2", @"key3":@"value3", @"key4":@"value4" }; NSLog(@"%@",dictionary3); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; } */ //调用NSDictionary静态方法生成字典 NSDictionary *dictionary4 = [NSDictionary dictionaryWithObject:@"value0" forKey:@"key0"]; NSLog(@"%@",dictionary4); /* { key0 = value0; } */ NSDictionary *dictionary5 = [NSDictionary dictionaryWithObjects:valueArray forKeys:keyArray]; NSLog(@"%@",dictionary5); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; } */ NSDictionary *dictionary6 = [NSDictionary dictionaryWithObjectsAndKeys:@"value0",@"key0",@"value1",@"key1",@"value2",@"key2",@"value3",@"key3",@"value4",@"key4", nil]; NSLog(@"%@",dictionary6); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; } */ }
- 字典基本常用用法
void arrayTest6() { NSDictionary *dictionary1 = [[NSDictionary alloc]initWithObjectsAndKeys:@"value0",@"key0", @"value1",@"key1", @"value2",@"key2", @"value3",@"key3", @"value4",@"key4", @"value4",@"key5", nil]; NSLog(@"%@",dictionary1); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; key5 = value4 } */ NSLog(@"%ld",dictionary1.count); /* 5 */ //输出特定元素 NSLog(@"%@",dictionary1[@"key0"]); NSLog(@"%@",[dictionary1 objectForKey:@"key0"]); /* value0 */ //获取所有key NSLog(@"%@",dictionary1.allKeys); /* ( key3, key1, key4, key2, key0 ) */ //获取所有value NSLog(@"%@",dictionary1.allValues); /* ( value3, value1, value4, value2, value0 ) */ //获取特定value对应的所有key NSLog(@"%@",[dictionary1 allKeysForObject:@"value4"]); /* ( key4, key5 ) */ //分别获取key对应的value,对于不存在的key，返回"not found" NSLog(@"%@",[dictionary1 objectsForKeys:@[@"key0",@"key1",@"key8"] notFoundMarker:@"not found"]); /* ( value0, value1, "not found" ) */ NSDictionary *dictionaryOther = @{@"key0":@"value0"}; BOOL result = [dictionary1 isEqualToDictionary:dictionaryOther]; NSLog(@"%hhd",result); /* 0 */ //保存到本地文件 [dictionary1 writeToFile:@"/Users/new/Desktop/dictionary.txt" atomically:YES]; /* <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>key0</key> <string>value0</string> <key>key1</key> <string>value1</string> <key>key2</key> <string>value2</string> <key>key3</key> <string>value3</string> <key>key4</key> <string>value4</string> <key>key5</key> <string>value4</string> </dict> </plist> */ //读取本地文件，反序列化为字典 NSDictionary* dictionary2 = [NSDictionary dictionaryWithContentsOfFile:@"/Users/new/Desktop/dictionary.txt"]; NSLog(@"%@",dictionary2); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; key5 = value4; } */ //修改字典元素值,如果key存在，则修改对应的value,如果key不存在，则插入一个新元素 [dictionary2 setValue:@"update value0" forKey:@"key0"]; NSLog(@"%@",dictionary2); /* { key0 = "update value0"; key1 = value1; key2 = value2; key3 = value3; key4 = value4; key5 = value4; } */ //插入一个新元素，该key不存在 [dictionary2 setValue:@"key not found" forKey:@"noKey"]; NSLog(@"%@",dictionary2); /* { key0 = "update value0"; key1 = value1; key2 = value2; key3 = value3; key4 = value4; key5 = value4; noKey = "key not found"; } */ }
- NSDictionary遍历
void dictionaryTest() { NSDictionary *dictionary1 = [[NSDictionary alloc]initWithObjectsAndKeys:@"value0",@"key0", @"value1",@"key1", @"value2",@"key2", @"value3",@"key3", @"value4",@"key4", @"value4",@"key5", nil]; //遍历方法一 for (NSString *key in dictionary1) { NSLog(@"%@ = %@",key,dictionary1[key]); } /* key3 = value3 key1 = value1 key4 = value4 key2 = value2 key0 = value0 key5 = value5 */ //遍历方法二 //NSEnumerator *objectEnumerator = [dictionary1 objectEnumerator]; //objectEnumerator获取value枚举 NSEnumerator *keyEumerator = [dictionary1 keyEnumerator]; //keyEnumerator获取key枚举 NSString *key = nil; while (key = [keyEumerator nextObject]) { NSLog(@"%@ = %@",key,dictionary1[key]); } /* key3 = value3 key1 = value1 key4 = value4 key2 = value2 key0 = value0 key5 = value5 */ //遍历方法三 [dictionary1 enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) { NSLog(@"%@ = %@",key,obj); }]; /* key3 = value3 key1 = value1 key4 = value4 key2 = value2 key0 = value0 key5 = value5 */ }
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NSMutableDictionary
NSMutableDictionary继承于NSDictionary，在此基础上新增加对元素新增、删除、更新等操作，如下代码演示
void mutableDictionaryTest() { NSMutableDictionary *mutableDictionary = [[NSMutableDictionary alloc]initWithCapacity:7]; NSLog(@"%ld",mutableDictionary.count); /* 0 */ [mutableDictionary setValue:@"value0" forKey:@"key0"]; [mutableDictionary setValue:@"value1" forKey:@"key1"]; [mutableDictionary setValue:@"value2" forKey:@"key2"]; [mutableDictionary setValue:@"value3" forKey:@"key3"]; [mutableDictionary setValue:@"value4" forKey:@"key4"]; [mutableDictionary setValue:@"value5" forKey:@"key5"]; [mutableDictionary setValue:@"value6" forKey:@"key6"]; [mutableDictionary setValue:@"value7" forKey:@"key7"]; NSLog(@"%ld",mutableDictionary.count); /* 8 */ NSLog(@"%@",mutableDictionary); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; key5 = value5; key6 = value6; key7 = value7; key8 = value8; } */ //删除元素 [mutableDictionary removeObjectForKey:@"key7"]; NSLog(@"%ld",mutableDictionary.count); /* 7 */ NSLog(@"%@",mutableDictionary); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; key5 = value5; key6 = value6; } */ //对于key存在，则修改对应的value,否则添加新元素 [mutableDictionary setValue:@"update value6" forKey:@"key6"]; NSLog(@"%@",mutableDictionary); //移除多个key对应的元素 [mutableDictionary removeObjectsForKeys:@[@"key6",@"key5"]]; NSLog(@"%@",mutableDictionary); /* { key0 = value0; key1 = value1; key2 = value2; key3 = value3; key4 = value4; } */ //移除所有元素 [mutableDictionary removeAllObjects]; NSLog(@"%ld",mutableDictionary.count); /* 0 */ }
以上代码在开发过程中比较常用，如果有不足之处，请给我留言