iOS Fundation-NSArray & NSMutableArray 使用详解

前几天把 NSString 和 NSMutableString 相关使用知识进行整理，对 API 进行列举然后介绍相关的使用方法。

但在开发过程中我们经常也会遇到多个字符串，多个不同类型数组。

在 iOS 中数组可以使用 NSArray 或者 NSMutableArray 来进行管理和使用。

NSArray 在 iOS 中储存的方式是连续的储存，而非链式存储。代码如下：

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NSArray *array = [[NSArray alloc] initWithObjects:@"First name", @"last name", nil];

进行断点打印 First name 和 last name 的位置，打印结果如下：

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Printing description of ((__NSCFConstantString *)0x000000010cdba0c8):
First name
Printing description of ((__NSCFConstantString *)0x000000010cdba0e8):
last name

NSArray

  • NSArray 初始化

NSArray 初始化方式：

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//使用类方法进行实现 `NSArray` 进行初始化
+ (instancetype)array;
+ (instancetype)arrayWithObject:(ObjectType)anObject;
+ (instancetype)arrayWithObjects:(const ObjectType _Nonnull [_Nonnull])objects count:(NSUInteger)cnt;
+ (instancetype)arrayWithObjects:(ObjectType)firstObj, ... NS_REQUIRES_NIL_TERMINATION;
+ (instancetype)arrayWithArray:(NSArray<ObjectType> *)array;
+ (nullable NSArray<ObjectType> *)arrayWithContentsOfURL:(NSURL *)url error:(NSError **)error API_AVAILABLE(macos(10.13), ios(11.0), watchos(4.0), tvos(11.0)) NS_SWIFT_UNAVAILABLE("Use initializer instead");

//使用实例方法进行 `NSArray` 进行初始化
- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder;
- (instancetype)initWithObjects:(ObjectType)firstObj, ... NS_REQUIRES_NIL_TERMINATION;
- (instancetype)initWithArray:(NSArray<ObjectType> *)array;
- (instancetype)initWithArray:(NSArray<ObjectType> *)array copyItems:(BOOL)flag;

- (nullable NSArray<ObjectType> *)initWithContentsOfURL:(NSURL *)url error:(NSError **)error  API_AVAILABLE(macos(10.13), ios(11.0), watchos(4.0), tvos(11.0));
  • NSArray 从文件和URL地址初始化
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+ (nullable NSArray<ObjectType> *)arrayWithContentsOfFile:(NSString *)path;
+ (nullable NSArray<ObjectType> *)arrayWithContentsOfURL:(NSURL *)url;
- (nullable NSArray<ObjectType> *)initWithContentsOfFile:(NSString *)path;
- (nullable NSArray<ObjectType> *)initWithContentsOfURL:(NSURL *)url;
- (BOOL)writeToFile:(NSString *)path atomically:(BOOL)useAuxiliaryFile;
- (BOOL)writeToURL:(NSURL *)url atomically:(BOOL)atomically;

NSArray 初始话的实例：

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NSArray *arrayString = @[@"First name", @"last name"];//直接初始化
NSArray *array = [[NSArray alloc] initWithObjects:@"First name", @"last name", nil];//使用系统 API
  • NSArray 经常使用 API
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//NSArray 中常见的一些属性
@property (readonly) NSUInteger count; //Object 的数量
@property (readonly, copy) NSString *description; //NSArray 的描述
@property (nullable, nonatomic, readonly) ObjectType firstObject; //数组中第一个 Object 对象
@property (nullable, nonatomic, readonly) ObjectType lastObject; // 数组中最后一个 Object 对象
@property (readonly, copy) NSData *sortedArrayHint; //转变为 NSData 数据

- (ObjectType)objectAtIndex:(NSUInteger)index; //获取 index 位置的 Object 对象
- (NSArray<ObjectType> *)arrayByAddingObject:(ObjectType)anObject; //为数组添加数据
- (NSArray<ObjectType> *)arrayByAddingObjectsFromArray:(NSArray<ObjectType> *)otherArray; //把两个数组合为一个数组
- (NSString *)componentsJoinedByString:(NSString *)separator; //把 NSArray 对象转变为 NSString 对象，并在第一个 Object 添加 NSString 
- (BOOL)containsObject:(ObjectType)anObject; //是否包含相关的 Object 对象

//对数组一些信息整理
- (NSString *)descriptionWithLocale:(nullable id)locale; 
- (NSString *)descriptionWithLocale:(nullable id)locale indent:(NSUInteger)level;
- (nullable ObjectType)firstObjectCommonWithArray:(NSArray<ObjectType> *)otherArray;
- (void)getObjects:(ObjectType _Nonnull __unsafe_unretained [_Nonnull])objects range:(NSRange)range NS_SWIFT_UNAVAILABLE("Use 'subarrayWithRange()' instead");
- (NSUInteger)indexOfObject:(ObjectType)anObject;
- (NSUInteger)indexOfObject:(ObjectType)anObject inRange:(NSRange)range;
- (NSUInteger)indexOfObjectIdenticalTo:(ObjectType)anObject;
- (NSUInteger)indexOfObjectIdenticalTo:(ObjectType)anObject inRange:(NSRange)range;
- (BOOL)isEqualToArray:(NSArray<ObjectType> *)otherArray;//比较两个字符是否相等

//对数组 NSArray 进行枚举处理
- (NSEnumerator<ObjectType> *)objectEnumerator;//使用正序实现
- (NSEnumerator<ObjectType> *)reverseObjectEnumerator;//使用倒叙实现

- (NSArray<ObjectType> *)sortedArrayUsingFunction:(NSInteger (NS_NOESCAPE *)(ObjectType, ObjectType, void * _Nullable))comparator context:(nullable void *)context;
- (NSArray<ObjectType> *)sortedArrayUsingFunction:(NSInteger (NS_NOESCAPE *)(ObjectType, ObjectType, void * _Nullable))comparator context:(nullable void *)context hint:(nullable NSData *)hint;
- (NSArray<ObjectType> *)sortedArrayUsingSelector:(SEL)comparator;
- (NSArray<ObjectType> *)subarrayWithRange:(NSRange)range;
//把 NSArray 写进地址
- (BOOL)writeToURL:(NSURL *)url error:(NSError **)error API_AVAILABLE(macos(10.13), ios(11.0), watchos(4.0), tvos(11.0));


- (void)makeObjectsPerformSelector:(SEL)aSelector NS_SWIFT_UNAVAILABLE("Use enumerateObjectsUsingBlock: or a for loop instead");
- (void)makeObjectsPerformSelector:(SEL)aSelector withObject:(nullable id)argument NS_SWIFT_UNAVAILABLE("Use enumerateObjectsUsingBlock: or a for loop instead");

- (NSArray<ObjectType> *)objectsAtIndexes:(NSIndexSet *)indexes;

- (ObjectType)objectAtIndexedSubscript:(NSUInteger)idx API_AVAILABLE(macos(10.8), ios(6.0), watchos(2.0), tvos(9.0));

//对 NSArray 进行遍历
- (void)enumerateObjectsUsingBlock:(void (NS_NOESCAPE ^)(ObjectType obj, NSUInteger idx, BOOL *stop))block API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));
- (void)enumerateObjectsWithOptions:(NSEnumerationOptions)opts usingBlock:(void (NS_NOESCAPE ^)(ObjectType obj, NSUInteger idx, BOOL *stop))block API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));//遍历时可以设置遍历的顺序
- (void)enumerateObjectsAtIndexes:(NSIndexSet *)s options:(NSEnumerationOptions)opts usingBlock:(void (NS_NOESCAPE ^)(ObjectType obj, NSUInteger idx, BOOL *stop))block API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));

- (NSUInteger)indexOfObjectPassingTest:(BOOL (NS_NOESCAPE ^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));
- (NSUInteger)indexOfObjectWithOptions:(NSEnumerationOptions)opts passingTest:(BOOL (NS_NOESCAPE ^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));
- (NSUInteger)indexOfObjectAtIndexes:(NSIndexSet *)s options:(NSEnumerationOptions)opts passingTest:(BOOL (NS_NOESCAPE^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));

- (NSIndexSet *)indexesOfObjectsPassingTest:(BOOL (NS_NOESCAPE ^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));
- (NSIndexSet *)indexesOfObjectsWithOptions:(NSEnumerationOptions)opts passingTest:(BOOL (NS_NOESCAPE ^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));
- (NSIndexSet *)indexesOfObjectsAtIndexes:(NSIndexSet *)s options:(NSEnumerationOptions)opts passingTest:(BOOL (NS_NOESCAPE ^)(ObjectType obj, NSUInteger idx, BOOL *stop))predicate API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));

- (NSArray<ObjectType> *)sortedArrayUsingComparator:(NSComparator NS_NOESCAPE)cmptr API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));
- (NSArray<ObjectType> *)sortedArrayWithOptions:(NSSortOptions)opts usingComparator:(NSComparator NS_NOESCAPE)cmptr API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));

- (NSUInteger)indexOfObject:(ObjectType)obj inSortedRange:(NSRange)r options:(NSBinarySearchingOptions)opts usingComparator:(NSComparator NS_NOESCAPE)cmp API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));

NSMutableArray

NSMutableArray 是继承自 NSArray 的子类：

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@interface NSMutableArray<ObjectType> : NSArray<ObjectType>
  • NSMutableArray 的初始化
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+ (instancetype)arrayWithCapacity:(NSUInteger)numItems;//以 item 数目来进行初始化

//从File 和 path 路径来实现 `NSMutableArray` 初始 
+ (nullable NSMutableArray<ObjectType> *)arrayWithContentsOfFile:(NSString *)path;
+ (nullable NSMutableArray<ObjectType> *)arrayWithContentsOfURL:(NSURL *)url;
- (nullable NSMutableArray<ObjectType> *)initWithContentsOfFile:(NSString *)path;
- (nullable NSMutableArray<ObjectType> *)initWithContentsOfURL:(NSURL *)url;
  • NSMutableArray一些基本函数
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- (void)addObject:(ObjectType)anObject;//添加
- (void)insertObject:(ObjectType)anObject atIndex:(NSUInteger)index;
- (void)removeLastObject;//如初最后一个
- (void)removeObjectAtIndex:(NSUInteger)index;//去处 index 位置 Object
- (void)replaceObjectAtIndex:(NSUInteger)index withObject:(ObjectType)anObject;//使用 Object 代替某个位置 Object
- (instancetype)init NS_DESIGNATED_INITIALIZER;//初始化
- (instancetype)initWithCapacity:(NSUInteger)numItems NS_DESIGNATED_INITIALIZER;//初始化数目
- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder NS_DESIGNATED_INITIALIZER;//
  • NSMutableArray高级应用
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//对现有的 array 数组添加 NSArray
- (void)addObjectsFromArray:(NSArray<ObjectType> *)otherArray;

//交换 idx1 和 idx2 两者之间的 Object 
- (void)exchangeObjectAtIndex:(NSUInteger)idx1 withObjectAtIndex:(NSUInteger)idx2;

//去除相关的 Object
- (void)removeAllObjects;
- (void)removeObject:(ObjectType)anObject inRange:(NSRange)range;
- (void)removeObject:(ObjectType)anObject;
- (void)removeObjectIdenticalTo:(ObjectType)anObject inRange:(NSRange)range;
- (void)removeObjectIdenticalTo:(ObjectType)anObject;
- (void)removeObjectsFromIndices:(NSUInteger *)indices numIndices:(NSUInteger)cnt API_DEPRECATED("Not supported", macos(10.0,10.6), ios(2.0,4.0), watchos(2.0,2.0), tvos(9.0,9.0));
- (void)removeObjectsInArray:(NSArray<ObjectType> *)otherArray;
- (void)removeObjectsInRange:(NSRange)range;

//替代 Object 的对象
- (void)replaceObjectsInRange:(NSRange)range withObjectsFromArray:(NSArray<ObjectType> *)otherArray range:(NSRange)otherRange;
- (void)replaceObjectsInRange:(NSRange)range withObjectsFromArray:(NSArray<ObjectType> *)otherArray;
- (void)setArray:(NSArray<ObjectType> *)otherArray;
- (void)sortUsingFunction:(NSInteger (NS_NOESCAPE *)(ObjectType,  ObjectType, void * _Nullable))compare context:(nullable void *)context;
- (void)sortUsingSelector:(SEL)comparator;

//加如相关的 Object 在 index 位置的修改
- (void)insertObjects:(NSArray<ObjectType> *)objects atIndexes:(NSIndexSet *)indexes;
- (void)removeObjectsAtIndexes:(NSIndexSet *)indexes;
- (void)replaceObjectsAtIndexes:(NSIndexSet *)indexes withObjects:(NSArray<ObjectType> *)objects;

- (void)setObject:(ObjectType)obj atIndexedSubscript:(NSUInteger)idx API_AVAILABLE(macos(10.8), ios(6.0), watchos(2.0), tvos(9.0));

//对当前的 NSArray 的数组进行整理
- (void)sortUsingComparator:(NSComparator NS_NOESCAPE)cmptr API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));
- (void)sortWithOptions:(NSSortOptions)opts usingComparator:(NSComparator NS_NOESCAPE)cmptr API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));

NSArray 和 NSMutableArray 区别

NSArray和NSMutableArray 两者都是对多个字符来进行储存，NSMutableArray 是 NSArray 的子类。两者的最基本的父类都是继承与 NSobject。

但是 NSMutableArray 是可变数组，可以动态修改数组中的相关参数和其中的长度。

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