Objective-C中NSArray类的解读

NSArray数组类是Objective-C语言中常用的也是重要的一个类，除了开发中常用到的一些基础功能，NSArray及其相关类中还封装了许多更加强大的功能。有机会总结了一下，与需要的朋友们分享。

NSArray中属性与方法：

//获取数组中元素个数
@property (readonly) NSUInteger count;
//通过下标获数组中的元素

• (ObjectType)objectAtIndex:(NSUInteger)index;

//初始化方法

• (instancetype)init;

//通过C语言风格的数组创建NSArray对象 需要注意，C数组中需要为Objective对象，cnt参数为C数组的长度
//如果cnt的值小于C数组的长度，则会对C数据进行截取赋值，如果大于则程序会崩溃

• (instancetype)initWithObjects:(const ObjectType [])objects count:(NSUInteger)cnt;

//数组的归档方法

• (nullable instancetype)initWithCoder:(NSCoder *)aDecoder;

//像数组中追加一个元素 这个方法会返回一个新的数组

• (NSArray *)arrayByAddingObject:(ObjectType)anObject;

//像数组中追加一组元素 这个方法会返回一个新的数组

• (NSArray)arrayByAddingObjectsFromArray:(NSArray)otherArray;

//返回一个字符串，将数组中的元素以separator为分隔符进行组合
/*
NSArray * array = @[@1,@2,@3,@4];
将打印1,2,3,4
NSString * res = [array componentsJoinedByString:@","];
*/

• (NSString )componentsJoinedByString:(NSString )separator;

//判断数组中是否包含某个元素

• (BOOL)containsObject:(ObjectType)anObject;

//数组的打印方法
@property (readonly, copy) NSString *description;

• (NSString *)descriptionWithLocale:(nullable id)locale;
• (NSString *)descriptionWithLocale:(nullable id)locale indent:(NSUInteger)level;

//获取第一个包含于另一个数组中的元素

• (nullable ObjectType)firstObjectCommonWithArray:(NSArray *)otherArray;

//将数组中一定范围的元素读取到一个C数组中 objects参数需要为分配好空间的C指针

• (void)getObjects:(ObjectType __unsafe_unretained [])objects range:(NSRange)range;

//获取某个元素在数值中的下标值

• (NSUInteger)indexOfObject:(ObjectType)anObject;

//获取某个范围内的元素的下标值

• (NSUInteger)indexOfObject:(ObjectType)anObject inRange:(NSRange)range;

//获取与给定元素相同的元素在数组中的最小下标值

• (NSUInteger)indexOfObjectIdenticalTo:(ObjectType)anObject;

//在一定范围内 获取与给定元素相同的元素在数组中的最小下标值

• (NSUInteger)indexOfObjectIdenticalTo:(ObjectType)anObject inRange:(NSRange)range;

//判断两个数组是否相同

• (BOOL)isEqualToArray:(NSArray *)otherArray;

//获取数组中第一个元素
@property (nullable, nonatomic, readonly) ObjectType firstObject NS_AVAILABLE(10_6, 4_0);
//获取数组中最后一个元素
@property (nullable, nonatomic, readonly) ObjectType lastObject;
//获取数组的枚举对象

• (NSEnumerator *)objectEnumerator;

//获取数组的逆向枚举对象

• (NSEnumerator *)reverseObjectEnumerator;

/*
这个属性可以获取一个已经排序数组的排序规则 在使用

• (NSArray)sortedArrayUsingFunction:(NSInteger ()(ObjectType, ObjectType, void __nullable))comparator context:(nullable void )context hint:(nullable NSData *)hint;

方法时可以将此排序规则传入
对于没有排序过的数组，使用

• (NSArray)sortedArrayUsingFunction:(NSInteger ()(ObjectType, ObjectType, void __nullable))comparator context:(nullable void )context;

方法会自动产生一个这样的排序规则
*/
@property (readonly, copy) NSData *sortedArrayHint;
//通过C排序函数进行排序
/*
示例：
NSInteger sort(id obj1, id obj2, void *context){

NSNumber *str1 =(NSNumber*) obj1;
NSNumber *str2 =(NSNumber*) obj2;
if ([str1 intValue] < [str2 intValue]) {
    return NSOrderedDescending;
}
else if([str1 intValue] == [str2 intValue])
{
    return NSOrderedSame;
}
return NSOrderedAscending;

}

• (void)viewDidLoad {
  [super viewDidLoad];
  NSArray * array = @[@1,@3,@2,@4];
  array = [array sortedArrayUsingFunction:sort context:nil];
  NSString * res = [array componentsJoinedByString:@","];
  NSLog(@"%@",res);

}
*/

• (NSArray)sortedArrayUsingFunction:(NSInteger ()(ObjectType, ObjectType, void __nullable))comparator context:(nullable void )context;

//通过C排序函数进行数组排序

• (NSArray)sortedArrayUsingFunction:(NSInteger ()(ObjectType, ObjectType, void __nullable))comparator context:(nullable void )context hint:(nullable NSData *)hint;

//使用函数选择器进行数组排序

• (NSArray *)sortedArrayUsingSelector:(SEL)comparator;

//获取数组一定范围的子数组

• (NSArray *)subarrayWithRange:(NSRange)range;

//将数组写入文件

• (BOOL)writeToFile:(NSString *)path atomically:(BOOL)useAuxiliaryFile;

//将数组写入指定url路径

• (BOOL)writeToURL:(NSURL *)url atomically:(BOOL)atomically;

//是数组中的所有元素调用某个方法选择器

• (void)makeObjectsPerformSelector:(SEL)aSelector;

//功能同上 支持传参

• (void)makeObjectsPerformSelector:(SEL)aSelector withObject:(nullable id)argument;

//获取一个下标集合所对应的元素

• (NSArray)objectsAtIndexes:(NSIndexSet )indexes;

//数组的下标方法 子类重写

• (ObjectType)objectAtIndexedSubscript:(NSUInteger)idx NS_AVAILABLE(10_8, 6_0);

//对数组中的元素进行枚举遍历

• (void)enumerateObjectsUsingBlock:(void (^)(ObjectType obj, NSUInteger idx, BOOL *stop))block NS_AVAILABLE(10_6, 4_0);

//对数组中的元素进行枚举遍历
/*
typedef NS_OPTIONS(NSUInteger, NSEnumerationOptions) {

NSEnumerationConcurrent = (1UL << 0),//正向枚举
NSEnumerationReverse = (1UL << 1),   //逆向枚举

};
*/

• (void)enumerateObjectsWithOptions:(NSEnumerationOptions)opts usingBlock:(void (^)(ObjectType obj, NSUInteger idx, BOOL *stop))block NS_AVAILABLE(10_6, 4_0);

//在一个下标集合中枚举

• (void)enumerateObjectsAtIndexes:(NSIndexSet )s options:(NSEnumerationOptions)opts usingBlock:(void (^)(ObjectType obj, NSUInteger idx, BOOL stop))block NS_AVAILABLE(10_6, 4_0);

//通过遍历的方式查找符合条件的元素下标

• (NSUInteger)indexOfObjectPassingTest:(BOOL (^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate NS_AVAILABLE(10_6, 4_0);

//通常 可以设置遍历方式

• (NSUInteger)indexOfObjectWithOptions:(NSEnumerationOptions)opts passingTest:(BOOL (^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate NS_AVAILABLE(10_6, 4_0);

//同上 在一定下标集合中遍历

• (NSUInteger)indexOfObjectAtIndexes:(NSIndexSet )s options:(NSEnumerationOptions)opts passingTest:(BOOL (^)(ObjectType obj, NSUInteger idx, BOOL stop))predicate NS_AVAILABLE(10_6, 4_0);

//通过遍历的方式查找所有符合条件的元素下标

• (NSIndexSet )indexesOfObjectsPassingTest:(BOOL (^)(ObjectType obj, NSUInteger idx, BOOL stop))predicate NS_AVAILABLE(10_6, 4_0);

//同上

• (NSIndexSet )indexesOfObjectsWithOptions:(NSEnumerationOptions)opts passingTest:(BOOL (^)(ObjectType obj, NSUInteger idx, BOOL stop))predicate NS_AVAILABLE(10_6, 4_0);

//同上

• (NSIndexSet )indexesOfObjectsAtIndexes:(NSIndexSet )s options:(NSEnumerationOptions)opts passingTest:(BOOL (^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate NS_AVAILABLE(10_6, 4_0);

//通过block进行数组排序

• (NSArray *)sortedArrayUsingComparator:(NSComparator)cmptr NS_AVAILABLE(10_6, 4_0);

//同上
/*
typedef NS_OPTIONS(NSUInteger, NSSortOptions) {

NSSortConcurrent = (1UL << 0),//同步排序
NSSortStable = (1UL << 4),//稳定排序

};

*/

• (NSArray *)sortedArrayWithOptions:(NSSortOptions)opts usingComparator:(NSComparator)cmptr NS_AVAILABLE(10_6, 4_0);

//二分查找的枚举参数
typedef NS_OPTIONS(NSUInteger, NSBinarySearchingOptions) {

NSBinarySearchingFirstEqual = (1UL << 8),
NSBinarySearchingLastEqual = (1UL << 9),
NSBinarySearchingInsertionIndex = (1UL << 10),

};
//对区域排序的数组进行二分查找

• (NSUInteger)indexOfObject:(ObjectType)obj inSortedRange:(NSRange)r options:(NSBinarySearchingOptions)opts usingComparator:(NSComparator)cmp NS_AVAILABLE(10_6, 4_0); // binary search

//创建对象

• (instancetype)array;

//通过一个元素创建数组对象

• (instancetype)arrayWithObject:(ObjectType)anObject;

//通过C数组创建数组对象

• (instancetype)arrayWithObjects:(const ObjectType [])objects count:(NSUInteger)cnt;

//通过一组元素创建数组对象

• (instancetype)arrayWithObjects:(ObjectType)firstObj, ... NS_REQUIRES_NIL_TERMINATION;

//通过另一个数组创建数组对象

• (instancetype)arrayWithArray:(NSArray *)array;

//初始化方法

• (instancetype)initWithObjects:(ObjectType)firstObj, ... NS_REQUIRES_NIL_TERMINATION;
• (instancetype)initWithArray:(NSArray *)array;
• (instancetype)initWithArray:(NSArray *)array copyItems:(BOOL)flag;

//通过文件创建数组

• (nullable NSArray)arrayWithContentsOfFile:(NSString )path;

//通过url创建数组

• (nullable NSArray)arrayWithContentsOfURL:(NSURL )url;

同上

• (nullable NSArray)initWithContentsOfFile:(NSString )path;
• (nullable NSArray)initWithContentsOfURL:(NSURL )url;

//获取数组所有元素 需要传入分配了内存的C指针

• (void)getObjects:(ObjectType __unsafe_unretained [])objects;

NSMutableArray中属性与方法：

//向数组中追加一个元素

• (void)addObject:(ObjectType)anObject;

//向数组某个位置插入一个元素

• (void)insertObject:(ObjectType)anObject atIndex:(NSUInteger)index;

//删除数组中最后一个元素

• (void)removeLastObject;

//删除数组中指定位置的元素

• (void)removeObjectAtIndex:(NSUInteger)index;

//替换数组中一个位置的元素

• (void)replaceObjectAtIndex:(NSUInteger)index withObject:(ObjectType)anObject;

//初始化

• (instancetype)init NS_DESIGNATED_INITIALIZER;
• (instancetype)initWithCapacity:(NSUInteger)numItems NS_DESIGNATED_INITIALIZER;
• (nullable instancetype)initWithCoder:(NSCoder *)aDecoder NS_DESIGNATED_INITIALIZER;

//通过数组来追加元素

• (void)addObjectsFromArray:(NSArray *)otherArray;

//交换两个元素

• (void)exchangeObjectAtIndex:(NSUInteger)idx1 withObjectAtIndex:(NSUInteger)idx2;

//删除所有元素

• (void)removeAllObjects;

//在一定范围内删除元素

• (void)removeObject:(ObjectType)anObject inRange:(NSRange)range;

//删除一个元素

• (void)removeObject:(ObjectType)anObject;

//删除指定范围内下标最小的某个元素

• (void)removeObjectIdenticalTo:(ObjectType)anObject inRange:(NSRange)range;

//删除某个元素 下标最小的

• (void)removeObjectIdenticalTo:(ObjectType)anObject;

//删除一定范围内的所有元素

• (void)removeObjectsFromIndices:(NSUInteger *)indices numIndices:(NSUInteger)cnt NS_DEPRECATED(10_0, 10_6, 2_0, 4_0);

//通过数组删除元素

• (void)removeObjectsInArray:(NSArray *)otherArray;

//通过范围删除元素

• (void)removeObjectsInRange:(NSRange)range;

//替换一组元素

• (void)replaceObjectsInRange:(NSRange)range withObjectsFromArray:(NSArray *)otherArray range:(NSRange)otherRange;

//替换一组元素

• (void)replaceObjectsInRange:(NSRange)range withObjectsFromArray:(NSArray *)otherArray;

//设置数组元素

• (void)setArray:(NSArray *)otherArray;

//进行数组排序

• (void)sortUsingFunction:(NSInteger ()(ObjectType, ObjectType, void __nullable))compare context:(nullable void *)context;

//进行数组排序

• (void)sortUsingSelector:(SEL)comparator;

//插入一组元素

• (void)insertObjects:(NSArray)objects atIndexes:(NSIndexSet )indexes;

//删除一组元素

• (void)removeObjectsAtIndexes:(NSIndexSet *)indexes;

//替换一组元素

• (void)replaceObjectsAtIndexes:(NSIndexSet )indexes withObjects:(NSArray)objects;

//设置某个下标对应的元素 子类覆写

• (void)setObject:(ObjectType)obj atIndexedSubscript:(NSUInteger)idx NS_AVAILABLE(10_8, 6_0);

//进行数组排序

• (void)sortUsingComparator:(NSComparator)cmptr NS_AVAILABLE(10_6, 4_0);

//进行数组排序

• (void)sortWithOptions:(NSSortOptions)opts usingComparator:(NSComparator)cmptr NS_AVAILABLE(10_6, 4_0);

//创建数组 numItems为元素个数

• (instancetype)arrayWithCapacity:(NSUInteger)numItems;

//通过文件创建数组

• (nullable NSMutableArray)arrayWithContentsOfFile:(NSString )path;

//通过url创建数组

• (nullable NSMutableArray)arrayWithContentsOfURL:(NSURL )url;

同上

• (nullable NSMutableArray)initWithContentsOfFile:(NSString )path;
• (nullable NSMutableArray)initWithContentsOfURL:(NSURL )url;