C# | Finding the index of first element in the array

GetLowerBound() Method is used to find the index of the first element of the specified dimension in the array.

Syntax:

public int GetLowerBound (int dimension);

Here, dimension is a zero-based dimension of the array whose lower bound needs to be determined.

Return Value: The return type of this method is System.Int32. This method returns the index of the first element of the specified dimension in the array.

Exception: This method will give IndexOutOfRangeException if the value of dimension is less than zero, or equal or greater than Rank.

Note:

• GetLowerBound(0) returns the starting index of the first dimension of the array, and GetLowerBound(Rank – 1) returns the starting index of the last dimension of the array.
• The GetLowerBound method always returns a value that indicates the index of the lower bound of the array, even if the array is empty.
• This method is an O(1) operation.

Below programs illustrate the use of GetLowerBound() Method:

Example 1:

// C# program to illustrate the GetLowerBound(Int32)
// method in 1-D array
using System;

public class GFG {

    // Main method
    static public void Main()
    {

        // 1-D Array
        int[] value = {1, 2, 3, 4, 5, 6, 7};

        // Get the index of the first element
        // in the given Array by using
        // GetLowerBound(Int32) method
        int myvalue = value.GetLowerBound(0);

        Console.WriteLine("Index: {0}", myvalue);
    }
}

Output:

Index: 0

Example 2:

// C# program to illustrate the GetLowerBound(Int32)
// method when the array is empty
using System;

public class GFG {

    // Main method
    static public void Main()
    {

        // Empty 1-D Array
        int[] value = {};

        // Get the index of the first element
        // in the given Array by using
        // GetLowerBound(Int32) method
        int myvalue = value.GetLowerBound(0);

        Console.WriteLine("Index: {0}", myvalue);
    }
}

Output:

Index: 0

Reference: https://docs.microsoft.com/en-us/dotnet/api/system.array.getlowerbound?view=netcore-2.1