Array.Clear() Method in C#

The Array.Clear() method in C# is used to reset one or more elements of an array to their default values. It modifies the existing array without changing its size.

• Numeric elements are reset to 0.
• bool elements are reset to false.
• Reference-type elements such as string are reset to null.

using System;

class GFG{
    static void Main()
    {
        int[] numbers = { 10, 20, 30, 40, 50 };

        Array.Clear(numbers, 1, 3);

        Console.WriteLine("Array after clearing:");

        foreach (int number in numbers)
        {
            Console.Write(number + " ");
        }
    }
}

Array after clearing:
10 0 0 0 50 

Syntax

Array.Clear(array, index, length);

Parameters

The Array.Clear() method accepts three parameters that specify the array and the range of elements to clear.

• array: The array whose elements need to be cleared.
• index: The starting index from which elements are cleared.
• length: The number of elements to clear.

How Array.Clear() Works

Array.Clear() resets a specified range of elements instead of removing them from the array. The range is determined by the index and length parameters.

Example

int[] numbers = { 10, 20, 30, 40, 50 };
Array.Clear(numbers, 1, 3);

Here, clearing starts at index 1 and continues for 3 elements. Therefore, the values at indexes 1, 2, and 3 are reset to 0.

The resulting array is: 10 0 0 0 50

Example: Clearing Elements from a String Array

using System;

class Program
{
    static void Main()
    {
        string[] names = { "John", "Alice", "Bob", "David" };

        Array.Clear(names, 1, 2);

        foreach (string name in names)
        {
            Console.WriteLine(name);
        }
    }
}

John


David

Explanation:

• The array contains four string elements.
• Array.Clear(names, 1, 2) starts at index 1 and clears two elements.
• "Alice" and "Bob" are reset to null.
• "John" and "David" remain unchanged.
• Console.WriteLine() displays an empty line for the null elements

Default Values After Clearing

The values assigned by Array.Clear() depend on the element type.

• int -> 0
• double -> 0
• bool -> false
• char -> '\0'
• Reference types such as string -> null

Exceptions

Array.Clear() can throw exceptions when the specified array, index, or length is invalid. The main exceptions are

• ArgumentNullException: Thrown when the specified array is null.
• ArgumentOutOfRangeException: Thrown when index or length is negative.
• ArgumentException: Thrown when the specified range extends beyond the bounds of the array.

Reference:

• https://learn.microsoft.com/en-us/dotnet/api/system.array.clear?view=netframework-4.7.2