C# Array.Clear()用法及代碼示例

此方法用於將數組中元素的範圍設置為每種元素類型的默認值。

用法:

public static void Clear (Array array, int index, int length);

參數：

array:這是一個需要清除其元素的數組。
index:它是要清除的元素範圍的起始索引。
length:這是要清除的元素數。

異常：

ArgumentNullException：如果數組為null
IndexOutOfRangeException：如果索引小於數組的下限，或者長度小於零，或者索引和長度的總和大於數組的大小。

下麵是說明Array.Clear()方法的示例：

示例1:

// C# program to demonstrate Array.Clear() 
// method for int type value 
using System; 
using System.Collections.Generic; 
  
public class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
  
        // Creating and initializing new the String 
        int[] myArr = {10, 20, 30, 40}; 
  
        // Display the values of the myArr. 
        Console.WriteLine("Array Before Operation:"); 
  
        // calling the PrintIndexAndValues() method  
        PrintIndexAndValues(myArr); 
        Console.WriteLine(); 
  
        Array.Clear(myArr, 1, 2); 
  
        // Display the values of myArr 
        Console.WriteLine("Array After Operation:"); 
  
        // calling the PrintIndexAndValues() method 
        PrintIndexAndValues(myArr); 
    } 
  
    // Defining the method PrintIndexAndValues  
    public static void PrintIndexAndValues(int[] myArr) 
    { 
        for (int i = 0; i < myArr.Length; i++) { 
            Console.WriteLine("{0}", myArr[i]); 
        } 
    } 
}

輸出：

Array Before Operation:
10
20
30
40

Array After Operation:
10
0
0
40

示例2:對於ArgumentNullException

// C# program to demonstrate 
// Array.Clear() method 
// for ArgumentNullException 
using System; 
using System.Collections.Generic; 
  
public class GFG { 
  
    public static void Main() 
    { 
  
        try { 
  
            // Creating and initializing  
            // new the Int with null 
            int[] myArr = null; 
  
            // Clearing the myArr 
            // using Clear() method 
            Console.WriteLine("Try to clear the element from null Array:"); 
            Array.Clear(myArr, 1, 2); 
  
            // Display the values of myArr 
            Console.WriteLine("Array after operation :"); 
  
            // calling the PrintIndexAndValues() method  
            PrintIndexAndValues(myArr); 
        } 
        catch (ArgumentNullException e) { 
  
            Console.WriteLine(); 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
        catch (IndexOutOfRangeException e) { 
  
            Console.WriteLine(); 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
  
    // Defining the method PrintIndexAndValues  
    public static void PrintIndexAndValues(int[] myArr) 
    { 
        for (int i = 0; i < myArr.Length; i++) { 
            Console.WriteLine("{0}", myArr[i]); 
        } 
    } 
}

輸出：

Try to clear the element from null Array:

Exception Thrown: System.ArgumentNullException

示例3:對於IndexOutOfRangeException

// C# program to demonstrate 
// Array.Clear() method 
// for IndexOutOfRangeException 
using System; 
using System.Collections.Generic; 
  
public class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
  
        try { 
  
            // Creating and initializing new Int array 
            int[] myArr = {10, 20, 30, 40}; 
  
            // Display the values of myArr 
            Console.WriteLine("Array Before Operation:"); 
  
            // calling the PrintIndexAndValues() method 
            PrintIndexAndValues(myArr); 
            Console.WriteLine(); 
  
            // Clearing the myArr 
            // using Clear() method 
            Console.WriteLine("Taking index out of bound:"); 
            Array.Clear(myArr, -1, 2); 
  
            // Display the values of myArr 
            Console.WriteLine("Array After Operation:"); 
  
            // calling the PrintIndexAndValues() method  
            PrintIndexAndValues(myArr); 
        } 
        catch (ArgumentNullException e) { 
  
            Console.Write("Exception Thrown :"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
        catch (IndexOutOfRangeException e) { 
            Console.Write("Exception Thrown :"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
  
    // Defining the method PrintIndexAndValues  
    public static void PrintIndexAndValues(int[] myArr) 
    { 
        for (int i = 0; i < myArr.Length; i++) { 
            Console.WriteLine("{0}", myArr[i]); 
        } 
    } 
}

輸出：

Array Before Operation:
10
20
30
40

Taking index out of bound:
Exception Thrown :System.IndexOutOfRangeException

參考：

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

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注：本文由純淨天空篩選整理自RohitPrasad3大神的英文原創作品 C# | Array.Clear() Method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。