Mono Class Library: System.Object Overview | Members

System.Object.Equals Method

Determines whether two object references are equal.

public static bool Equals (object objA, object objB)

Parameters

objA
Documentation for this section has not yet been entered.
objB
Documentation for this section has not yet been entered.

Returns

true if one or more of the following statements is true:

  • objA and objB refer to the same object,
  • objA and objB are both null references,
  • objA is not null and objA.Equals(objB ) returns true;

otherwise returns false.

Remarks

This static method checks for null references before it calls objA.Equals(objB ) and returns false if either objA or objB is null. If the Equals(object obj) implementation throws an exception, this method throws an exception.

Example

The following example demonstrates the object.Equals(object) method.

C# Example

using System;

public class MyClass {
   public static void Main() {
   string s1 = "Tom";
   string s2 = "Carol";
   Console.WriteLine("Object.Equals(\"{0}\", \"{1}\") => {2}", 
      s1, s2, Object.Equals(s1, s2));

   s1 = "Tom";
   s2 = "Tom";
   Console.WriteLine("Object.Equals(\"{0}\", \"{1}\") => {2}", 
      s1, s2, Object.Equals(s1, s2));

   s1 = null;
   s2 = "Tom";
   Console.WriteLine("Object.Equals(null, \"{1}\") => {2}",
       s1, s2, Object.Equals(s1, s2));

   s1 = "Carol";
   s2 = null;
   Console.WriteLine("Object.Equals(\"{0}\", null) => {2}", 
       s1, s2, Object.Equals(s1, s2));

   s1 = null;
   s2 = null;
   Console.WriteLine("Object.Equals(null, null) => {2}", 
       s1, s2, Object.Equals(s1, s2));
   }
}
   

The output is

Object.Equals("Tom", "Carol") => False
Object.Equals("Tom", "Tom") => True
Object.Equals(null, "Tom") => False
Object.Equals("Carol", null) => False
Object.Equals(null, null) => True

Requirements

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0