C # deleting elements in the list

Content is the result of others' work, collected by hl3292

1. I used an inverse loop.

 for (int i = list.Count - 1; i >= 0; i--)
{
if (list[i].NO == item.NO)
  {
  list.RemoveAt(i);
  }
}

Comments:

Removeall should be used for efficiency. It is equivalent to a traversal, which switches all elements that meet the conditions to the front of the list,
Then, the non-conforming elements are deleted at one time, and the efficiency is O (n,
If a row is deleted, all the following elements must be moved forward after each row is deleted. The efficiency is n ^ 2!

2. However, if you use other lists, you do not need to reproduce the clone method.

Code

   public void RemoveItemFromList(ref List <A> list, A item)
        {
            List <A> tempList = new List <A>();
foreach (A a in list)
            {
if (a.NO != item.NO && !tempList.Contains(a))
                    tempList.Add(a);
            }
            list = tempList;
        }

This can also be done.