    bool result = (obj is MyClass); // Better than using &#39;as&#39;

The equivalent of Java’s `obj.getClass().isInstance(otherObj)` in C# is as follows:

    bool result = obj.GetType().IsAssignableFrom(otherObj.GetType());

Note that while both Java and C# work on the runtime type object (Java `java.lang.Class` ≣ C# `System.Type`) of an `obj` (via `.getClass()` vs `.getType()`), Java’s `isInstance` takes an object as its argument, whereas C#’s `IsAssignableFrom` expects another `System.Type` object.

Depends, use `is` if you don&#39;t want to use the result of the cast and use `as` if you do. You hardly ever want to write:

    if(foo is Bar) {
        return (Bar)foo;
    }
    
Instead of:

    var bar = foo as Bar;
    if(bar != null) {
        return bar;
    }

just off the top of my head, you could also do:

    bool result = ((obj as MyClass) != null)

Not sure which would perform better. I&#39;ll leave it up to someone else to benchmark :)


Below code can be alternative to `IsAssignableFrom`. 

    parentObject.GetType().IsInstanceOfType(inheritedObject)

See [Type.IsInstanceOfType](https://msdn.microsoft.com/en-us/library/system.type.isinstanceoftype%28v=vs.110%29.aspx) description in MSDN.

What is the equivalent of Java&#39;s `System.currentTimeMillis()` in C#?

Java System.currentTimeMillis() equivalent in C#

What is the way to avoid phpunit having to call the constructor for a mock object? Otherwise I would need a mock object as constructor argument, another one for that etc. The api seems to be like this:

    getMock($className, $methods = array(), array $arguments = array(),
            $mockClassName = &#39;&#39;, $callOriginalConstructor = TRUE,
            $callOriginalClone = TRUE, $callAutoload = TRUE)

I don&#39;t get it to work. It still complains about the constructor argument, even with `$callOriginalConstructor` set to false.

I only have one object in the constructor and it is a dependency injection. So I don&#39;t think I have a design problem there.

phpunit avoid constructor arguments for mock

I know of `is` and `as` for `instanceof`, but what about the reflective [isInstance()][1] method?

  [1]: http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Class.html#isInstance(java.lang.Object)


What is the C# equivalent to Java&#39;s isInstance()?

<p>I know of <code>is</code> and <code>as</code> for <code>instanceof</code>, but what about the reflective <a href="http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Class.html#isInstance(java.lang.Object)" target="_blank" rel="noopener noreferrer">isInstance()</a> method?</p>


Given the following simple example:

        List&lt;string&gt; list = new List&lt;string&gt;() { &quot;One&quot;, &quot;Two&quot;, &quot;Three&quot;, &quot;three&quot;, &quot;Four&quot;, &quot;Five&quot; };

        CaseInsensitiveComparer ignoreCaseComparer = new CaseInsensitiveComparer();

        var distinctList = list.Distinct(ignoreCaseComparer as IEqualityComparer&lt;string&gt;).ToList();

It appears the CaseInsensitiveComparer is not actually being used to do a case-insensitive comparison.  

In other words **distinctList**  contains the same number of items as **list**.   Instead I would expect, for example, &quot;Three&quot; and &quot;three&quot; be considered equal.

Am I missing something or is this an issue with the Distinct operator?


LINQ Distinct operator, ignore case?

Anyone know a good and effective way to search/match for a byte pattern in an byte[] array and then return the positions.

For example

    byte[] pattern = new byte[] {12,3,5,76,8,0,6,125};

    byte[] toBeSearched = new byte[] {23,36,43,76,125,56,34,234,12,3,5,76,8,0,6,125,234,56,211,122,22,4,7,89,76,64,12,3,5,76,8,0,6,125}


byte[] array pattern search

I know you can do it file by file.

Is there any way to do this in one step for all files in a project?

Remove unused namespaces across a whole project or solution at once

Given a method signature:

    public bool AreTheSame&lt;T&gt;(Expression&lt;Func&lt;T, object&gt;&gt; exp1, Expression&lt;Func&lt;T, object&gt;&gt; exp2)

What would be the most efficient way to say if the two expressions are the same? This only needs to work for simple expressions, by this I mean all that would be &quot;supported&quot; would be simple MemberExpressions, eg c =&gt; c.ID.

An example call might be:

    AreTheSame&lt;User&gt;(u1 =&gt; u1.ID, u2 =&gt; u2.ID); --&gt; would return true

Most efficient way to test equality of lambda expressions

How can I build XML in C#?

I want to discover at run-time ONLY the static Methods of a class, how can I do this?
Or, how to differentiate between static and non-static methods.

How can I check if a method is static using reflection?

How can I check whether a variable is defined in Ruby?  Is there an `isset`-type method available?


Checking if a variable is defined?

I&#39;m currently considering the use of Reflection classes (ReflectionClass and ReflectionMethod mainly) in my own MVC web framework, because I need to automatically instanciate controller classes and invoke their methods without any required configuration (&quot;convention over configuration&quot; approach).

I&#39;m concerned about performance, even though I think that database requests are likely to be bigger bottlenecks than the actual PHP code.

So, I&#39;m wondering if anyone has any good or bad experience with PHP 5 Reflection from a performance point of view.

Besides, I&#39;d be curious to know if any one of the popular PHP frameworks (CI, Cake, Symfony, etc.) actually use Reflection.

PHP 5 Reflection API performance

In C# is there a technique using reflection to determine if a method has been added to a class as an extension method?

Given an extension method such as the one shown below is it possible to determine that Reverse() has been added to the string class?

    public static class StringExtensions
    {
        public static string Reverse(this string value)
        {
            char[] cArray = value.ToCharArray();
            Array.Reverse(cArray);
            return new string(cArray);
        }
    }

We&#39;re looking for a mechanism to determine in unit testing that the extension method was appropriately added by the developer.  One reason to attempt this is that it is possible that a similar method would be added to the actual class by the developer and, if it was, the compiler will pick that method up.

Reflection to Identify Extension Methods

I have got a template class as follows:

    class MyClass&lt;T&gt;
    {
        T field;
        public void myMethod()
        {
           field = new T(); // gives compiler error
        }
    }

How do I create a new instance of T in my class?

Instantiating object of type parameter

How do I find out a name of class that created an instance of an object in Python if the function I am doing this from is the base class of which the class of the instance has been derived?

Was thinking maybe [the inspect module][1] might have helped me out here, but it doesn&#39;t seem to give me what I want. And short of parsing the `__class__` member, I&#39;m not sure how to get at this information.


  [1]: https://docs.python.org/2/library/inspect.html &quot;inspect — Inspect live objects&quot;

Getting the class name of an instance?

Say I have a variable named `choice` it is equal to 2. How would I access the name of the variable? Something equivalent to

    In [53]: namestr(choice)
    Out[53]: &#39;choice&#39;

for use in making a dictionary. There&#39;s a good way to do this and I&#39;m just missing it.

EDIT:

The reason to do this is thus. I am running some data analysis stuff where I call the program with multiple parameters that I would like to tweak, or not tweak, at runtime. I read in the parameters I used in the last run from a .config file formated as

    filename
    no_sig_resonance.dat
    
    mass_peak
    700
    
    choice
    1,2,3

When prompted for values, the previously used is displayed and an empty string input will use the previously used value.

My question comes about because when it comes to writing the dictionary that these values have been scanned into. If a parameter is needed I run `get_param` which accesses the file and finds the parameter. 

I think I will avoid the problem all together by reading the .`config` file once and producing a dictionary from that. I avoided that originally for... reasons I no longer remember. Perfect situation to update my code!

How can you print a variable name in python?

Say you have a javascript object like this:

    var data = { foo: &#39;bar&#39;, baz: &#39;quux&#39; };

You can access the properties by the property name:

    var foo = data.foo;
    var baz = data[&quot;baz&quot;];

But is it possible to get these values if you don&#39;t know the name of the properties? Does the unordered nature of these properties make it impossible to tell them apart?

In my case I&#39;m thinking specifically of a situation where a function needs to accept a series of name-value pairs, but the names of the properties may change.

My thoughts on how to do this so far is to pass the names of the properties to the function along with the data, but this feels like a hack. I would prefer to do this with introspection if possible.

How do I access properties of a javascript object if I don&#39;t know the names?

Given a class C in Python, how can I determine which file the class was defined in? I need something that can work from either the class C, or from an instance off C.

The reason I am doing this, is because I am generally a fan off putting files that belong together in the same folder. I want to create a class that uses a Django template to render itself as HTML. The base implementation should infer the filename for the template based on the filename that the class is defined in.

Say I put a class LocationArtifact in the file &quot;base/artifacts.py&quot;, then I want the default behaviour to be that the template name is &quot;base/LocationArtifact.html&quot;.

How do I get the filepath for a class in Python?

How can I get a list (in the form of an `NSArray` or `NSDictionary`) of a given object properties in Objective-C?  

Imagine the following scenario: I have defined a parent class which just extends `NSObject`, that holds an `NSString`, a `BOOL` and an `NSData` object as properties. Then I have several classes which extend this parent class, adding a lot of different properties each.  

Is there any way I could implement an instance method on the *parent* class that goes through the whole object and returns, say, an `NSArray` of each of the (child) class properties as `NSStrings` that are *not* on the parent class, so I can later use these `NSString` for KVC?

Get an object properties list in Objective-C

Which of the following is better?

    a instanceof B

or

    B.class.isAssignableFrom(a.getClass())

The only difference that I know of is, when &#39;a&#39; is null, the first returns false, while the second throws an exception. Other than that, do they always give the same result?

What is the difference between instanceof and Class.isAssignableFrom(...)?

What is the preferred method to achieve the C++ equivalent of java&#39;s `instanceof`?

C++ equivalent of java&#39;s instanceof

I&#39;m using Eclipse to generate `.equals()` and `.hashCode()`, and there is an option labeled &quot;Use &#39;instanceof&#39; to compare types&quot;.  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;
    if (getClass() != obj.getClass())
      return false;

Using `instanceof`:

    if (obj == null)
      return false;
    if (!(obj instanceof MyClass))
      return false;

I usually check the `instanceof` option, and then go in and remove the &quot;`if (obj == null)`&quot; check. (It is redundant since null objects will always fail `instanceof`.)  Is there any reason that&#39;s a bad idea?

Any reason to prefer getClass() over instanceof when generating .equals()?

In my particular case:

    callback instanceof Function

or 

    typeof callback == &quot;function&quot;

does it even matter, what&#39;s the difference?

**Additional Resource:**

JavaScript-Garden [typeof][1] vs [instanceof][2]


  [1]: http://bonsaiden.github.com/JavaScript-Garden/#types.typeof
  [2]: http://bonsaiden.github.com/JavaScript-Garden/#types.instanceof

Content Type	Original Author	Original Content on Stackoverflow
Question	diegogs	View Question on Stackoverflow
Solution 1 - C#	Ana Betts	View Answer on Stackoverflow
Solution 2 - C#	Konrad Rudolph	View Answer on Stackoverflow
Solution 3 - C#	David	View Answer on Stackoverflow
Solution 4 - C#	CodingWithSpike	View Answer on Stackoverflow
Solution 5 - C#	Youngjae	View Answer on Stackoverflow

What is the C# equivalent to Java's isInstance()?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Solution 4 - C#

Solution 5 - C#

phpunit avoid constructor arguments for mock

Java System.currentTimeMillis() equivalent in C#

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