remove and return items from list matching predicate in csharp

In C#, you can remove and return items from a list that match a specific predicate using the List<T>.RemoveAll and List<T>.FindAll methods.

The RemoveAll method removes all items from the list that match the specified predicate and returns the number of items removed. Here's an example:


main.cs
List<int> myList = new List<int> { 1, 2, 3, 4, 5 };
int numRemoved = myList.RemoveAll(x => x % 2 == 0); // remove all even numbers
Console.WriteLine($"Removed {numRemoved} items from list."); // Output: Removed 2 items from list.
230 chars
4 lines

The FindAll method returns a new List<T> containing all items from the original list that match the specified predicate. Here's an example:


main.cs
List<string> myList = new List<string> { "apple", "banana", "cherry", "date", "elderberry" };
List<string> fruits = myList.FindAll(x => x.Length <= 5); // find all fruits with 5 or fewer characters
foreach (string fruit in fruits)
{
    Console.WriteLine(fruit);
}
// Output:
// apple
// cherry
// date
303 chars
11 lines

You can see that the fruits list only contains items that match the predicate (apple, cherry, and date), while the original myList is unchanged.

similar csharp code snippets

sort a list by name and remove middle element in csharp

remove a character from a string in csharp

remove an element from the beginning of an array in csharp

remove an element from an array at a specific index in csharp

remove a node from the middle of a linked list in csharp

remove a key-value pair from a map in csharp

remove an element from the middle of an array in csharp

find the kth largest number in a list in csharp

remove a character from a string at a specific index in csharp

remove a node from the end of a linked list in csharp

related categories