在这里我要说一下，ios开发的知识点都偏于基础，我只记录了一些基础的知识点，并进行了扩展，适合入门的朋友：
【IOS初学者】UITableView与自定义UITableViewCell
【IOS初学者】bundle知识点总结
【IOS开发初学者】UINavigationController详解

NSArray

初始化

   //1)创建一个空数组NSArray *arr1 = [NSArray array];//创建数组,只有一个元素NSArray *arr2 = [NSArray arrayWithObject:@"aaa"];//创建数组,有多个元素// nil 表示数组赋值结束NSArray *arr3 = [NSArray arrayWithObjects:@"aaa",@"bbb", nil];//调用对象方法,创建数组NSArray *arr4 = [[NSArray alloc] initWithObjects:@"aaa",@"bbb", nil];//用一个数组可以创建另外一个数组NSArray *arr5 = [NSArray arrayWithArray:arr3];//使用@NSArray *arr6 = @[@"aaa",@"bbb",@"ccc",@"ddd"];复制代码

常用方法

    //获取数组的长度NSLog(@"%ld",arr3.count);//根据下标,获取下标对应的对象NSLog(@"%@",[arr3 objectAtIndex:1]);  NSLog(@"%@",arr3[1]);//返回元素的下标NSUInteger loc = [arr3 indexOfObject:@"bbb"];NSLog(@"%ld",loc);//数组中是否包含了某个元素if([arr3 containsObject:@"gggg"]){     NSLog(@"包含此元素");}else{NSLog(@"不包含");}NSLog(@"arr5 = %@",arr5);复制代码

对应log：

2017-02-24 09:35:12.836 TestArray[7023:601929] 2
2017-02-24 09:35:12.837 TestArray[7023:601929] bbb
2017-02-24 09:35:12.837 TestArray[7023:601929] bbb
2017-02-24 09:35:12.837 TestArray[7023:601929] 1
2017-02-24 09:35:12.837 TestArray[7023:601929] 不包含
2017-02-24 09:35:12.837 TestArray[7023:601929] arr5 = (aaa,bbb
)复制代码

遍历

   //普通的方式,通过下标访问for (int i=0; i<arr3.count; i++) {NSLog(@"-> %@",arr3[i]);}// 快速枚举法 for循环的增强形式for (NSString * str in arr3) {NSLog(@"---> %@",str);}//使用block的方式,进行访问[arr3 enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {if(idx == 2){*stop = YES;  //停止}else{NSLog(@"idx = %ld,obj = %@",idx,obj);}}];复制代码

打印log如下：

2017-02-24 09:46:33.215 TestArray[7047:609202] -> aaa
2017-02-24 09:46:33.215 TestArray[7047:609202] -> bbb
2017-02-24 09:46:33.215 TestArray[7047:609202] ---> aaa
2017-02-24 09:46:33.215 TestArray[7047:609202] ---> bbb
2017-02-24 09:46:33.215 TestArray[7047:609202] idx = 0,obj = aaa
2017-02-24 09:46:33.215 TestArray[7047:609202] idx = 1,obj = bbb
Program ended with exit code: 0复制代码

读写

• 写

 NSArray *array = [NSArray     arrayWithObjects:@"one",@"zbz",@"cgx",@"sb",@"cjk",@"senni", nil];BOOL isWrite =  [array writeToFile:@"/Users/xxxx/Desktop/arr.xml" atomically:YES];复制代码

• 读

 NSArray *readArr = [NSArray arrayWithContentsOfFile:@"/Users/xxxx/Desktop/arr.xml"];复制代码

NSArray与字符串

• 数组拼接字符串

 NSArray *arr6 = @[@"aaa",@"bbb",@"ccc",@"ddd"];NSString *str = [arr6 componentsJoinedByString:@"-"];NSLog(@"str = %@",str);复制代码

• 字符串拆分为数组

NSArray *arr7 = [str componentsSeparatedByString:@"-"];NSLog(@"%@",[arr7 firstObject]);NSLog(@"%@",[arr7 lastObject]);NSLog(@"%@",arr7[1]);复制代码

看下打印log：

2017-02-24 09:58:04.852 TestArray[7107:619117] str = aaa-bbb-ccc-ddd
2017-02-24 09:58:04.852 TestArray[7107:619117] aaa
2017-02-24 09:58:04.853 TestArray[7107:619117] ddd
2017-02-24 09:58:04.853 TestArray[7107:619117] bbb
Program ended with exit code: 0复制代码

NSMutableArray

初始化

  NSMutableArray *arr1 = [NSMutableArray array];//创建的时候初始化一个元素NSMutableArray *arr2 = [NSMutableArray arrayWithObject:@"aaa"];//创建数组的时候,初始化多个元素NSMutableArray *arr3 = [NSMutableArray arrayWithObjects:@"bbb",@"ccc",@"ddd",nil];//创建一个数组,并且指定长度,NSMutableArray *arr4 = [NSMutableArray arrayWithCapacity:5];复制代码

操作

• 添加

  [arr1 addObject:@"ccc"];
  [arr1 insertObject:@"ddd" atIndex:0];复制代码

• 删除

  /删除指定元素
  [arr1 removeObject:@"aaa"];
  //根据角标删除元素
  [arr1 removeObjectAtIndex:1];
  //删除所有元素
  [arr1 removeAllObjects];复制代码

• 修改

  [arr3 replaceObjectAtIndex:1 withObject:@"aaa"];
  arr3[1] = @"ccc";复制代码

• 查找

  BOOL isSearch = [arr3 containsObject:@"ddd"];
  NSLog(@"%d",isSearch);复制代码

• 交换

  NSMutableArray *arr5 =[NSMutableArray arrayWithObjects:@1,@2,@3,@4,@5, nil];
  [arr5 exchangeObjectAtIndex:0 withObjectAtIndex:4];
  NSLog(@"%@",arr5);复制代码

  遍历

  NSMutableArray的遍历可以使用NSArray的方式进行遍历

NSDictionary

创建

NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"lnj", @"name", @"12345678", @"phone", @"天朝", @"address", nil];NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};复制代码

获取元素

[dict objectForKey:@"name”];
dict[@"name”];复制代码

遍历

   NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};for (NSString *key in dict) {NSLog(@"key = %@, value = %@", key, dict[key]);}复制代码

或

  [dict enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) {NSLog(@"key = %@, value = %@", key, obj);}];复制代码

读写

• 读

  NSDictionary *newDict = [NSDictionary dictionaryWithContentsOfFile:@"/Users/LNJ/Desktop/dict.plist"];NSLog(@"newDict = %@", newDict);复制代码

• 写

  NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};BOOL flag = [dict writeToFile:@"/Users/LNJ/Desktop/dict.plist" atomically:YES];NSLog(@"flag = %i", flag);复制代码

NSMutableDictionary

初始化

NSMutableDictionary *dic2 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"v1",@"key1",@"v2",@"key2",nil];NSMutableDictionary *dict1 = [NSMutableDictionary dictionary]; NSMutableDictionary *dict2 = [NSMutableDictionary dictionaryWithCapacity:3];复制代码

添加元素

[dic2 addEntriesFromDictionary:dic3];
[dic2 setValue:@"value3" forKey:@"key3"];复制代码

删除元素

//删除指定key
[dic1 removeObjectForKey@"key1"];
//删除指定key数组
NSArray *array = [NSArray arrayWithObjects:@"key1", nil];
[dic2 removeObjectsForKeys:array];
//移除字典所有对象
[dic1 removeAllObjects];复制代码

修改元素

 [dict1 setObject:@"zhaosi" forKey:@"ls"];//简写形式dict1[@"ls"] = @"xxxxx";NSLog(@"%@",dict1);复制代码

遍历

 NSMutableDictionary *dictionary3 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"value",@"key",@"value2",@"key2",@"value3",@"key3",@"value4",@"key4",@"value5",@"key5",@"value6",@"key6", nil];for (id key in dictionary3) {id obj = [dictionary3 objectForKey:key];NSLog(@"快速枚举--->obj= %@",obj);}//一般枚举NSArray *keys = [dictionary3 allKeys];float length = [keys count];for (int i = 0; i < length; i ++) {id key = [keys objectAtIndex:i];id obj = [dictionary3 objectForKey:key];NSLog(@"一般枚举--->%@",obj);}//通过枚举类枚举NSEnumerator *enumerator3 = [dictionary3 keyEnumerator];id key = [enumerator3 nextObject];while (key) {id obj = [dictionary3 objectForKey:key];NSLog(@"通过枚举类枚举--->%@",obj);key = [enumerator3 nextObject];}复制代码