Objective-C的数组比C++，Java的数组强大在于，NSArray保存的对象可以是不同的对象。但只能保存对象，int ,char,double等基本数据类型不能直接保存，需要通过转换成对象才能加入数组。

NSArray不可变数组

• [array count] : 数组的长度。

• [arrayWithObjects; ...] :向数组对象初始化赋值。这里可以写任意对象的指针,结尾必须使用nil

void demoNSArray() {NSObject *object = [[NSObject alloc] init];NSArray *array = [NSArray arrayWithObjects:@"a",@"b",@"c",object, nil];NSLog(@"array的数量是： %ld.",[array count]);//遍历数组for(NSObject *obj in array) {NSLog(@"%@",obj);}NSLog(@"%@",[array objectAtIndex:2]);}2016-10-10 11:11:03.471886 ArrayDemo[17100:1359352] array的数量是： 4.
2016-10-10 11:11:03.472329 ArrayDemo[17100:1359352] a
2016-10-10 11:11:03.472359 ArrayDemo[17100:1359352] b
2016-10-10 11:11:03.472373 ArrayDemo[17100:1359352] c
2016-10-10 11:11:03.472498 ArrayDemo[17100:1359352] <NSObject: 0x100403630>
2016-10-10 11:11:03.472518 ArrayDemo[17100:1359352] c

NSMutableArray可变数组

• [NSMutableArray arrayWithCapacity:6] :初始化可变数组对象的长度，如果后面代码继续添加数组超过长度6以后NSMutableArray的长度会自动扩充，6是自己可以设置的颗粒度。

• [array addObject:...] : 向可变数组尾部添加数据对象。

• [array addObjectsFromArray:..] :向可变数组尾部添加一个数组对象。

普通使用

void demoNSMutableArray() {NSObject *object = [[NSObject alloc] init];NSMutableArray *array = [NSMutableArray arrayWithCapacity:6];[array addObject:@"1"];[array addObject:object];[array addObject:@"2"];[array addObject:@"3"];[array addObject:@"4"];[array insertObject:@"搅局的" atIndex:2]; //插入对象//遍历数组for(NSObject *obj in array) {NSLog(@"%@",obj);}NSRange range = NSMakeRange(0, 3);//object对象在此范围内则删除 否则不删除任何对象[array removeObject:object inRange:range];//遍历数组for(NSObject *obj in array) {NSLog(@"%@",obj);}}2016-10-10 11:11:03.472518 ArrayDemo[17100:1359352] c
2016-10-10 11:11:03.472556 ArrayDemo[17100:1359352] 1
2016-10-10 11:11:03.472583 ArrayDemo[17100:1359352] <NSObject: 0x100300120>
2016-10-10 11:11:03.472599 ArrayDemo[17100:1359352] 搅局的
2016-10-10 11:11:03.472611 ArrayDemo[17100:1359352] 2
2016-10-10 11:11:03.472621 ArrayDemo[17100:1359352] 3
2016-10-10 11:11:03.472632 ArrayDemo[17100:1359352] 42016-10-10 11:11:03.472661 ArrayDemo[17100:1359352] 1
2016-10-10 11:11:03.472673 ArrayDemo[17100:1359352] 搅局的
2016-10-10 11:11:03.472683 ArrayDemo[17100:1359352] 2
2016-10-10 11:11:03.472694 ArrayDemo[17100:1359352] 3
2016-10-10 11:11:03.472704 ArrayDemo[17100:1359352] 4

NSRange range = NSMakeRange(0,3); 设置一个范围为 0 到 3 之间。
[array removeObject:obj inRange:range] : 设置在一个范围内删除数据，如果这个范围内没有删除的这个对象则不会删除任何东西。例子中因为obj对象在 数组 0 到 3的范围内，所以obj就被删除掉了。

删除对象removeObject和removeObjectIdenticalTo

• [array removeObject:(id)] :删除数组中指定元素，根据对象isEqual消息判断。

• [array removeObjectIdenticalTo:(id)] : 删除数组中指定元素,根据对象的地址判断

• [array removeObjectIdenticalTo:(id) inRange:(NSRange)] : 在指定范围内删除指定的元素。

• [array removeObjectsInArray:(NSArray *)] :删除一个数组的元素。

void doRemove() {NSString *str1 = [[NSString alloc] init];NSString *str2 = [[NSString alloc] init];NSString *str3 = [str1 stringByAppendingFormat:@"字符串"];NSString *str4 = [str2 stringByAppendingFormat:@"字符串"];NSMutableArray *array = [NSMutableArray arrayWithCapacity:6];[array addObject:@"对象"];[array addObject:str3];[array addObject:str4];for(NSObject *obj in array) {NSLog(@"数组对象: %@",obj);}//比字符串值if ([str3 isEqual:str4]) {NSLog(@"str1 == str2");}//比对象的地址if (str3 == str4) {NSLog(@"str1 == str2");}//[array removeObject:(id)] :删除数组中指定元素，根据对象isEqual消息判断,即根据对象的值判断。
//    [array removeObject:str3]; //删除所有值为str3的对象//[array removeObjectIdenticalTo:(id)] : 删除数组中指定元素,根据对象的地址判断[array removeObjectIdenticalTo:str3]; //只删除str3对象for(NSObject *obj in array) {NSLog(@"数组对象: %@",obj);}}2016-10-10 11:19:17.050519 ArrayDemo[17200:1366118] 数组对象: 对象
2016-10-10 11:19:17.050541 ArrayDemo[17200:1366118] 数组对象: 字符串
2016-10-10 11:19:17.050554 ArrayDemo[17200:1366118] 数组对象: 字符串
2016-10-10 11:19:17.050571 ArrayDemo[17200:1366118] isEqual str1 == str2
2016-10-10 11:19:17.050590 ArrayDemo[17200:1366118] 数组对象: 对象
2016-10-10 11:19:17.050642 ArrayDemo[17200:1366118] 数组对象: 字符串

替换某索引值对应的对象

void doReplace() {NSObject *object = [[NSObject alloc] init];NSMutableArray *array = [NSMutableArray arrayWithCapacity:5];[array addObject:@"1"];[array addObject:@"2"];[array addObject:@"3"];[array addObject:@"4"];[array addObject:object];for(NSObject *obj in array) {NSLog(@"数组对象: %@",obj);}[array replaceObjectAtIndex:2 withObject:@"被替换的对象"];for(NSObject *obj in array) {NSLog(@"数组对象: %@",obj);}
}2016-10-10 11:19:17.050666 ArrayDemo[17200:1366118] 数组对象: 1
2016-10-10 11:19:17.050679 ArrayDemo[17200:1366118] 数组对象: 2
2016-10-10 11:19:17.050689 ArrayDemo[17200:1366118] 数组对象: 3
2016-10-10 11:19:17.050700 ArrayDemo[17200:1366118] 数组对象: 4
2016-10-10 11:19:17.050724 ArrayDemo[17200:1366118] 数组对象: <NSObject: 0x1004001d0>2016-10-10 11:19:17.050737 ArrayDemo[17200:1366118] 数组对象: 1
2016-10-10 11:19:17.050747 ArrayDemo[17200:1366118] 数组对象: 2
2016-10-10 11:19:17.050758 ArrayDemo[17200:1366118] 数组对象: 被替换的对象
2016-10-10 11:19:17.050769 ArrayDemo[17200:1366118] 数组对象: 4
2016-10-10 11:19:17.050813 ArrayDemo[17200:1366118] 数组对象: <NSObject: 0x1004001d0>

数组迭代的遍历方法

void doIterator() {NSObject *object = [[NSObject alloc] init];NSMutableArray *array = [NSMutableArray arrayWithCapacity:5];[array addObject:@"1"];[array addObject:@"2"];[array addObject:@"3"];[array addObject:@"4"];[array addObject:object];NSEnumerator *enumearator = [array objectEnumerator];id obj;while(obj = [enumearator nextObject]) {NSLog(@"数组对象: %@",obj);}
}2016-10-10 11:19:17.051273 ArrayDemo[17200:1366118] 数组对象: 1
2016-10-10 11:19:17.051300 ArrayDemo[17200:1366118] 数组对象: 2
2016-10-10 11:19:17.051368 ArrayDemo[17200:1366118] 数组对象: 3
2016-10-10 11:19:17.051425 ArrayDemo[17200:1366118] 数组对象: 4
2016-10-10 11:19:17.051491 ArrayDemo[17200:1366118] 数组对象: <NSObject: 0x1004001d0>