C# List - Removing items while looping / iterating [duplicate]

Answer 1

You can use List<T>.RemoveAll to handle this:

data.RemoveAll(elem => elem == "One");

Answer 2

        var data = new List<string>() { "One", "Two", "Three" };
        data.RemoveAll(p=>p=="One");

Answer 3

If you need to remove elements then you must iterate backwards so you can remove elements from the end of the list:

var data=new List<string>(){"One","Two","Three"};
for(int i=data.Count - 1; i > -1; i--)
{
    if(data[i]=="One")
    {
        data.RemoveAt(i);
    }
}

However, there are more efficient ways to do this with LINQ (as indicated by the other answers).

Answer 4

Why don't you just simply decrement the iterator variable?

var data=new List<string>(){"One","Two","Three"};
for(int i=0 ; i<data.Count ; i++){
  if(data[i]=="One"){
    data.RemoveAt(i);
    i--; // <<<<<<<<<<<
  }
}

Answer 5

var data=new List<string>(){"One","Two","Three"};
for(int i=0; i<data.Count; ){
  if(data[i]=="One") data.RemoveAt(i);
  else ++i;
}

Answer 6

The general solution below makes a copy of the list and handles the negative index:

foreach (void item_loopVariable in MyList.ToList) {
    item = item_loopVariable;

}