C# | Copy OrderedDictionary elements to Array instance at the specified index (original) (raw)

Last Updated : 01 Feb, 2019

OrderedDictionary.CopyTo(Array, Int32) method is used to copy the OrderedDictionary elements to a one-dimensional Array object at the specified index.Syntax:

public void CopyTo (Array array, int index);

Parameters:

array: It is the one-dimensional Array which is the destination of the DictionaryEntry objects copied from OrderedDictionary. The Array must have zero-based indexing.index: it is the zero-based index in array at which copying begins.

Note: OrderedDictionary.CopyTo(Array, Int32) method doesn't provide any guarantee to maintain the order of the elements in the OrderedDictionary collection. Below programs illustrate the use of the above-discussed method:Example 1:

CSharp `

// C# code to copy OrderedDictionary to // Array instance at the specified index using System; using System.Collections; using System.Collections.Specialized;

class GFG {

// Driver code
public static void Main()
{

    // Creating a orderedDictionary named myDict
    OrderedDictionary myDict = new OrderedDictionary();

    // Adding key and value in myDict
    myDict.Add("key1", "value1");
    myDict.Add("key2", "value2");
    myDict.Add("key3", "value3");
    myDict.Add("key4", "value4");
    myDict.Add("key5", "value5");

    DictionaryEntry[] myArr = new DictionaryEntry[myDict.Count];

    // Copying OrderedDictionary to Array
    // instance at the specified index
    myDict.CopyTo(myArr, 0);

    // Displaying elements in myArr
    for (int i = 0; i < myArr.Length; i++) {
        Console.WriteLine(myArr[i].Key + "-->" 
                            + myArr[i].Value);
    }
}

}

`

Output:

key3-->value3 key4-->value4 key5-->value5 key2-->value2 key1-->value1

Example 2:

CSharp `

// C# code to copy OrderedDictionary to // Array instance at the specified index // that give ArgumentOutOfRangeException // due to the negative index using System; using System.Collections; using System.Collections.Specialized;

class GFG {

// Driver code
public static void Main()
{

    // Creating a orderedDictionary named myDict
    OrderedDictionary myDict = new OrderedDictionary();

    // Adding key and value in myDict
    myDict.Add("C", "1");
    myDict.Add("C++", "2");
    myDict.Add("Java", "3");
    myDict.Add("C#", "4");

    DictionaryEntry[] myArr = new DictionaryEntry[myDict.Count];

    // Copying OrderedDictionary to Array
    // instance at the specified index
    // This will raise "ArgumentOutOfRangeException"
    // as index is less than 0
    myDict.CopyTo(myArr, -2);

    // Displaying elements in myArr
    for (int i = 0; i < myArr.Length; i++) {
        Console.WriteLine(myArr[i].Key + "-->" 
                            + myArr[i].Value);
    }
}

}

`

Runtime Error:

Unhandled Exception: System.ArgumentOutOfRangeException: Non-negative number required. Parameter name: arrayIndex

Reference:

Similar Reads