NSArray

//定义并初始化
NSArray *array = [@"123", @"456",@"789"];
//遍历数组
方法1：
for(id obj in array){
  NSLog(@"%@", obj);
}
方法2:
[array enumerateObjectsusingBlock:^(id obj, NSUInteger idx, BOOL *stop){
  NSLog(@"obj = %@, index = %i", obj, idx);
}];
方法3:
NSEnumerator *enumerator = [array objectEnumerator];
//数组派生
NSArray *array = [NSArray arrayWithObjcts@"1",@"2",@"3",nil];
NSArray *array1 = [array arrayByAddingObject:@"4"];//此时array并没有改变
//追加生成新的数组
[array1 arrayByAddingObjectsFromArray:[NSArray arrayWithObjects:@"5",@"6"]];
//根据已有数组形成新的数组
[array1 subarrayWithRange:NSMakeRange(1,  3)];
//数组连接形成一个字符串
[array componentsJoinedByString:@","]；
//将数组写入文件
NSString *path = @"/Uers/Sunjian/Desktop/array.xml";
[array writeToFile:path atomically:YES];
//从文件中读取数组
NSArray *array3 = [NSArray arrayWithContentsOfFile:path];
//数据排序
NSArray *array = [NSArray arrayWithObjects:@"3",@"1",@"2", nil];
NSArray *array1 = [array sortedArrayUsingSelector:@selector(compare:)];
//增
[array addObject:array1];
//删
[array removeObject:array];
[array removeLastObject];
[array removeAllObjects];