C# equivalent of the vb isNothing

VB.Net IsNothing Function returns a Boolean value indicating whether an expression has no object assigned to it. There is no direct, 100% equivalent of the Vb.Net function IsNothing, but the test against null accomplishes the same thing.

VB.Net

 
Public Class Form1
  Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim str As String
    str = "Helo World"
    If Not IsNothing(str) Then
      MsgBox("String is not null")
    Else
      MsgBox("String is null")
    End If
  End Sub
End Class

IsNothing is intended to work on reference types. It returns True if the expression represents an object variable that currently has no object assigned to it; otherwise, it returns False.

C#

 
using System;
using System.Windows.Forms;
namespace WindowsFormsApplication4
{
  public partial class Form1 : Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void button1_Click(object sender, EventArgs e)
    {
      String str = "Helo World!!";
      if (str != null)
        MessageBox.Show("String is Not Null");
      else
        MessageBox.Show("String is Null");
    }
  }
}

The null keyword is specific design feature in the C# language. It is a literal that represents a null reference, one that does not refer to any object. null is the default value of reference-type variables

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