学步园

 5、数组

NSArray *array = [NSAray arrayWithObject:@"one",nil];

NSMutableArray *marray = [ NSMutableArray  arrayWithArray:array];

  5.1 监查数组，测试一个数组是否包含某个对象

    if(marray containsObject:"foru")

             nslog(the index is %d，[marray indexOfobject:@"foru"]);

 5.2数组转换为字符串

[array componesJoinedByString:@" "]

6、创建与实用字典

 NSDictionary NSMutabledictonary

NSMutableDictionary *mdic = [NSMutableDictionary dictionary];

[dict setObject:@"1", forkey:@"A"];

[dict setObject:@"2", forkey:@"B"];

常用方法：

[dict objectForKey:@"C"]

removeObjectForKey，allKeys，

7、将集合写入文件

NSString *path [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/ArraySample.plist"];

if(array writeToFile:path atomically:YES)  NSLog（@"ok"）；

8、从文件取出放入数组

   NSArray *newArray =[NSArray arrayWithContentsOfFile:path];