C# | Remove the first occurrence from the StringCollection (original) (raw)

Last Updated : 01 Feb, 2019

StringCollection class is a new addition to the .NET Framework class library that represents a collection of strings. StringCollection class is defined in the System.Collections.Specialized namespace. StringCollection.Remove(String) method is used to remove the first occurrence of a specific string from the StringCollection.Syntax:

public void Remove (string value);

Here, value is the string which is to be removed from the StringCollection. The value can be null.Note:

• Duplicate strings are allowed in StringCollection.
• Only the first occurrence is removed. To remove all occurrences of the specified string, use RemoveAt(IndexOf(value)) repeatedly while IndexOf does not return -1.
• If the StringCollection does not contain the specified object, the StringCollection remains unchanged. No exception is thrown.
• This method performs a linear search; therefore, this method is an O(n) operation, where n is Count.

Example:

CSHARP `

// C# code to remove the first // occurrence of a specific string // from the StringCollection using System; using System.Collections; using System.Collections.Specialized;

class GFG {

// Driver code
public static void Main()
{

    // creating a StringCollection named myCol
    StringCollection myCol = new StringCollection();

    // creating a string array named myArr
    String[] myArr = new String[] {"A", "A", "A", "B", "C",
                                       "C", "D", "D", "E"};

    // Copying the elements of a string
    // array to the end of the StringCollection.
    myCol.AddRange(myArr);

    Console.WriteLine("Elements in StringCollection are : ");

    // Displaying elements in StringCollection
    // named myCol
    foreach(Object obj in myCol)
        Console.WriteLine(obj);

    // Removing the first occurrence of
    // "A" from the StringCollection
    myCol.Remove("A");

    Console.WriteLine("Elements in StringCollection are : ");

    // Displaying elements in StringCollection
    // named myCol
    foreach(Object obj in myCol)
        Console.WriteLine(obj);

    // Removing the first occurrence of
    // "C" from the StringCollection
    myCol.Remove("C");

    Console.WriteLine("Elements in StringCollection are : ");

    // Displaying elements in StringCollection
    // named myCol
    foreach(Object obj in myCol)
        Console.WriteLine(obj);

    // Removing the first occurrence of
    // "A" from the StringCollection
    myCol.Remove("A");

    Console.WriteLine("Elements in StringCollection are : ");

    // Displaying elements in StringCollection
    // named myCol
    foreach(Object obj in myCol)
        Console.WriteLine(obj);

    // Removing the first occurrence of
    // "Z" from the StringCollection
    // It would not throw exception even
    // if "Z" does not exist in myCol
    myCol.Remove("Z");

    Console.WriteLine("Elements in StringCollection are : ");

    // Displaying elements in StringCollection
    // named myCol
    foreach(Object obj in myCol)
        Console.WriteLine(obj);
}

}

`

Output:

Elements in StringCollection are : A A A B C C D D E Elements in StringCollection are : A A B C C D D E Elements in StringCollection are : A A B C D D E Elements in StringCollection are : A B C D D E Elements in StringCollection are : A B C D D E

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.collections.specialized.stringcollection.remove?view=netframework-4.7.2