I would like to define an abstract base class X and enforce the following: a) every concrete class Y that inherits from X define a constructor Y(int x) b) it should be possible to test whether two Y objects are equal. For a, one not very good solution is to put a pure virtual fromInt method in X which concrete class will have to defi...
In F#, the equality operator (=) is generally extensional, rather than intensional. That's great! Unfortunately, it appears to me that F# does not use pointer equality to short-cut these extensional comparisons. For instance, this code: type Z = MT | NMT of Z ref // create a Z: let a = ref MT // make it point to itself: a := NMT a ...
How do you handle object equality for java objects managed by hibernate? In the 'hibernate in action' book they say that one should favor business keys over surrogate keys. Most of the time, i do not have a business key. Think of addresses mapped to a person. The addresses are keeped in a Set and displayed in a Wicket RefreshingView (wit...
Does "-eq" in Powershell test reference equality (like "==" in c#) or does it do the equivalent of calling Object.Equals() ...
public class abc1 { private String s; public abc1(String s){this.s=s;} public static void main(String args[]) { HashSet<Object> hs=new HashSet<Object>(); abc1 a1= new abc1("abc"); abc1 a2= new abc1("abc"); String s1= new String("abc"); String s2= new String("abc"); hs.add(a1); hs.add(a2); hs.add(s1); hs.add(s2); ...
I want my Food class to be able to test whenever it is equal to another class. I will later use it against a List, and I want to use its List.Contains() method. Should I implement IEquatable or just override Object.Equals()? From MSDN: This method determines equality by using the default equality comparer, as defined by the objec...
To check if a type is a subclass of another type in C#, it's easy: typeof (SubClass).IsSubclassOf(typeof (BaseClass)); // returns true However, this will fail: typeof (BaseClass).IsSubclassOf(typeof (BaseClass)); // returns false Is there any way to check whether a type is either a subclass OR of the base class itself, without usin...
Hi, Is there a quick way to compare equality of more than one values in C#? something like: if (5==6==2==2){ //do something } Thanks ...
From MBUnit I am trying to check if the values of two objects are the same using Assert.AreSame(RawDataRow, result); However I am getting the following fail: Expected Value & Actual Value : {RawDataRow: CentreID = "CentreID1", CentreLearnerRef = "CentreLearnerRef1", ContactID = 1, DOB = 2010-05-05T00:00:00.0000000, Email = "Email1",...
>>> x = "google" >>> x is "google" True >>> x = "google.com" >>> x is "google.com" False >>> Can someone give me some hints why its like that? Edit: to make sure above, I have just tested on python 2.5.4, 2.6.5, 2.7b2, python 3.1 on windows and python 2.7b1 on linux Looks its consistence across all, so its by design and Am I missing ...
Try the following in the Immediate window: object a1 = "a"; object a2 = "a"; a1==a2 // outputs false and you'll see that a1 == a2 outputs false. However, at runtime in either a window app or console, you'll get true: object t1 = "a"; object t2 = "a"; MessageBox.Show((t1 == t2).ToString()); // outputs true The runtime behavior is c...
AS3 Code: import flash.utils.Dictionary; var num1:Number = Number.NaN; var num2:Number = Math.sqrt(-1); var dic:Dictionary = new Dictionary( true ); trace(num1); //NaN trace(num2); //NaN dic[num1] = "A"; trace( num1 == num2 ); //false trace( num1 === num2 ); //false trace( dic[num1] ); //A trace( dic[num2] ); //A Concerning the key co...
I'm having a problem comparing strings in a Unit Test in C# 4.0 using Visual Studio 2010. This same test case works properly in Visual Studio 2008 (with C# 3.5). Here's the relevant code snippet: byte[] rawData = GetData(); string data = Encoding.UTF8.GetString(rawData); Assert.AreEqual("Constant", data, false, CultureInfo.InvariantCu...
If I want to compare the contents of a XMlDocument, is it just like this? XmlDocument doc1 = GetDoc1(); XmlDocument doc2 = GetDoc2(); if(doc1 == doc2) { } I am not checking if they are both the same object reference, but if the CONTENTS of the xml are the same. ...
I'm working on a function that given some settings - such as line spacing, the output (in string form) is modified. In order to test such scenarios, I'm using string literals, as shown below for the expected result. The method, using a string builder, (AppendLine) generates the said output. One issue I have run into is that of comparing...
if(0 == ('Pictures')) { echo 'true'; } why it's giving me 'true' ? ...
Probably an extremely simple answer to this extremely simple question: I'm reading "C Primer Plus" by Pratta and he keeps using the example while (scanf("%d", &num) == 1)... Is the == 1 really necessary? It seems like one could just write: while (scanf("%d", &num)) It seems like the equality test is unnecessary since scanf returns...
Hey guys, I'm using DB2 and I have two tables that have a million+ rows in them. Is there a query I can create that will check the two tables to see if all the values in the two are the same? Or, what is the best way to do this? Thanks, Tyler ...
Hi, I am trying some code around object equality in java. As I have read somewhere hashCode() is a number which is generated by applying the hash function. Hash Function can be different for each object but can also be same. At the object level, it returns the memory address of the object. Now, I have sample program, which I run ...
I want to test for example int orderId = myRepository.SubmitOrder(orderA); orderB = myRepository.GetOrder(orderId); Assert.AreEqual(orderA, orderB); // fail Obviously I need a value comparison here, but I don't want to have to provide an overridden Equals implementation for all of my classes purely for the sake of testing (it wouldn...