Hello, i recently stumbled upon a seemingly weird behavior that Google completely failed to explain. using Microsoft.VisualStudio.TestTools.UnitTesting; class TestClass { public override bool Equals(object obj) { return true; } } [TestMethod] public void TestMethod1() { TestClass t = new TestClass (); Assert...
I wondered about the best way to implement a correct, flexible and fast Equals in C#, that can be used for practically any class and situation. I figured that a specialized Equals (taking an object of the actual class as parameter) is needed for performance. To avoid code duplication, the general Equals ought to call the specialized Equa...
i have a class whose equality is based on 2 fields such that if either one is equal then the objects of this type are considered equal. how can i write a hashCode() function for such an equals() so that the general contract of hashCode being equal when equals returns true is preserved? public class MyClass { int id; String name; ...
Say I have a Point2 class, and I want to implement the following Equals: public override bool Equals ( object obj ) public bool Equals ( Point2 obj ) This is from the Effective C# 3 book: public override bool Equals ( object obj ) { // STEP 1: Check for null if ( obj == null ) { return false; } // STEP 3: e...
I'm using Eclipse to generate .equals() and .hashCode(), and there is an option labeled "Use 'instanceof' to compare types". The default is for this option to be unchecked and use .getClass() to compare types. Is there any reason I should prefer .getClass() over instanceof? Without using instanceof: if (obj == null) return false; i...
How can I find out what caused equals() to return false? I'm not asking about a sure-way, always right approach, but of something to aid in the development process. Currently I have to step into the equals() calls (usually a tree of them) until one of them is false, then step into it, ad nauseam. I thought about using the object graph,...
Can we do something similar to List.Contains(myItem) in order to check if a property on an item in the list equals a property on myItem. (We have considered Contains and Exists, something like: if (orderLines.Contains(myLine)) { ... } but cannot get a simple expression.) We would like something as simple as the following: if (ord...
Is there any significant difference between the following? SELECT a.name, b.name FROM a, b WHERE a.id = b.id AND a.id = 1 AND SELECT a.name, b.name FROM a INNER JOIN b ON a.id = b.id WHERE a.id = 1 Do SO users have a preference of one over the other? ...
Background I am using interface-based programming on a current project and have run into a problem when overloading operators (specifically the Equality and Inequality operators). Assumptions I'm using C# 3.0, .NET 3.5 and Visual Studio 2008 UPDATE - The Following Assumption was False! Requiring all comparisons to use Equals ra...
Background I have two objects which have bidirectional association between them in a C# project I am working on. I need to be able to check for value equality (vs reference equality) for a number of reasons (e.g to use them in collections) and so I am implementing IEquatable and the related functions. Assumptions I am using C# 3.0, ....
I wanted to make sure about something in Java: If I have a Character or an Integer or a Long and those sort of things, should I use equals or is == sufficient? I know that with strings there are no guarantees that there is only one instance of each unique string, but I'm not sure about other boxed types. My intuition is to use equals, ...
With NHibernate entities, you are meant to override Equals and GetHashCode. Is it a good idea to override the == operator to use the .Equals implementation also? ...
In attempting to create an initial, failing unit test in Visual Studio Professonal 2008's test capabilities, I can't seem to get Assert.ReferenceEquals() to correctly fail when an object instance is not equal to a null reference. Note that object.ReferenceEquals() is correctly returning false for this same comparison. Here is my class c...
While trying to verify to myself, that C# Equals for IEnumerables is a reference equals, I found something odd. With the following setup in NUnit var a = (IEnumerable<string>)(new[] { "one", "two" }); var b = (IEnumerable<string>)(new[] { "one", "two" }); this test Assert.IsFalse(a.Equals(b)); passes, while this test Assert.AreNot...
I've defined a C# class with a string member. For all intents an purposes, think of this class as being a subclass of string (except that's not allowed). I'm using it to represent a strongly typed string field that matches a specific format (I've simplified this significantly). public class field { private readonly string m_field;...
I have a condition in a silverlight application that comapres 2 strings, for some reason when I use '==' it returns false while .Equals() returns true. Here is the code : if (((ListBoxItem)lstBaseMenu.SelectedItem).Content.Equals("Energy Attack")) { // Execute code } if (((ListBoxItem)lstBaseMenu.SelectedItem).Content == "Energy At...
I have this code here, which is intended to allow any type of arguments: public static void AreEqual(object expectedValue, object actualValue) { if (expectedValue == actualValue) { HttpContext.Current.Response.Write("Equal"); } else { HttpContext.Current.Response.Write("Not Equal"); } } If I call it using a couple of ints it do...
Hi Guys, Its been one of those days can someone help me out with this. I have 2 Stock Objects which I want to compare properties of at runtime. One instance is the cached instance, the other is a new stock instance which has just been delivered to my system, which may or may not equal the cached instance. See below where m is a method ...
I've got multiple classes that, for certain reasons, do not follow the official Equals contract. In the overwritten GetHashCode() these classes simply return 0 so they can be used in a Hashmap. Some of these classes implement the same interface and there are Hashmaps using this interface as key. So I figured that every class should at l...
I have implemented successfully the reflectionEquals method, with a list of excluded fields. return EqualsBuilder.reflectionEquals(this, obj, new String[] {"files", "notes", "status"}); However, I recently compiled my program on Java 1.5 and now I get the following error when the program hits the above line: java.lang.NoSuchMet...