数组嵌套数组内部数组数据替换

//获取嵌套数组内模型
DataModel *seleModel = self.modelsArray[indexPath.section][indexPath.row];

//获取内部数组
 NSMutableArray * arr =   [NSMutableArray arrayWithArray:self.modelsArray[indexPath.section]];

//删除内部可变数组的行
 //  [arr removeObjectAtIndex:indexPath.row];
 
//替换内部可变数组的行
 [arr replaceObjectAtIndex:indexPath.row withObject:seleModel];

//重新赋值
   self.modelsArray[indexPath.section] =  arr;

end