There&#39;s no difference, `==` is a synonym for `=` (for the C/C++ people, I assume). See [here][1], for example.

You could double-check just to be *really* sure or just for your interest by looking at the [bash source code][2], should be somewhere in the parsing code there, but I couldn&#39;t find it straightaway.


  [1]: http://tldp.org/LDP/abs/html/comparison-ops.html
  [2]: http://ftp.gnu.org/gnu/bash/

I want to make some unit-tests for my app, and I need to compare two arrays. Since `array.__eq__` returns a new array (so `TestCase.assertEqual` fails), what is the best way to assert for equality?


Currently I&#39;m using

    self.assertTrue((arr1 == arr2).all())

but I don&#39;t really like it

Best way to assert for numpy.array equality?

Is there a method which returns the width ( in pixels ) of a text to be drawn on an Android canvas using the drawText() method according to the Paint used to draw it?

Measuring text width to be drawn on Canvas ( Android )

In `bash`, what&#39;s the difference, if any, between the equal and double equal test operators?

    [[ &quot;a&quot; = &quot;a&quot; ]] &amp;&amp; echo equal || echo not-equal
    [[ &quot;a&quot; == &quot;a&quot; ]] &amp;&amp; echo equal || echo not-equal
    [[ &quot;a&quot; = &quot;b&quot; ]] &amp;&amp; echo equal || echo not-equal
    [[ &quot;a&quot; == &quot;b&quot; ]] &amp;&amp; echo equal || echo not-equal

results in:

    equal
    equal
    not-equal
    not-equal

bash string equality

In <code>bash</code>, what's the difference, if any, between the equal and double equal test operators?
<pre><code class="hljs language-lua">[[ "a" = "a" ]] &#x26;&#x26; echo equal || echo not-equal
[[ "a" == "a" ]] &#x26;&#x26; echo equal || echo not-equal
[[ "a" = "b" ]] &#x26;&#x26; echo equal || echo not-equal
[[ "a" == "b" ]] &#x26;&#x26; echo equal || echo not-equal
</code></pre>
results in:
<pre><code class="hljs">equal
equal
not-equal
not-equal
</code></pre>

I&#39;m new to bash shell scripting, and have come across a challenge. I know I can reload my &quot;.profile&quot; file by just doing:

    . .profile

but I&#39;m trying to execute the same in a bash script I&#39;m writing and it is just not working. 
Any ideas? Anything else I can provide to clarify?

Thanks

Reload .profile in bash shell script (in unix)?

I need to process a number of directories, determine what files in them are symlinks, and what they link to. This sounds simple, but I have no control over the presence of control or other characters in the file names, and I need a robust solution.

So, given a file of arbitrary name, how do I safely determine what it links to, when the link destination can also have arbitrary contents?

In Bash, how do I safely determine what a soft link points to?

I&#39;m trying to write a post-commit hook for SVN, which is hosted on our development server.  My goal is to try to automatically checkout a copy of the committed project to the directory where it is hosted on the server.  However I need to be able to read only the last directory in the directory string passed to the script in order to checkout to the same sub-directory where our projects are hosted.

For example if I make an SVN commit to the project &quot;example&quot;, my script gets &quot;/usr/local/svn/repos/example&quot; as its first argument.  I need to get just &quot;example&quot; off the end of the string and then concat it with another string so I can checkout to &quot;/server/root/example&quot; and see the changes live immediately. 

Get last dirname/filename in a file path argument in Bash

I want to be able to run a command from my machine using ssh and pass through the environment variable `$BUILD_NUMBER`


Here&#39;s what I&#39;m trying:

    ssh pvt@192.168.1.133 &#39;~/tools/myScript.pl $BUILD_NUMBER&#39;


`$BUILD_NUMBER` is set on the machine making the ssh call and since the variable doesn&#39;t exist on the remote host, it doesn&#39;t get picked up.

How do I pass the value of `$BUILD_NUMBER` ?

Passing variables in remote ssh command

How can I send an HTML email using a shell script?

Sending HTML mail using a shell script

Yet another list-comparing question.

    List&lt;MyType&gt; list1;
    List&lt;MyType&gt; list2;

I need to check that they both have the same elements, regardless of their position within the list. Each **MyType** object may appear multiple times on a list. Is there a built-in function that checks this? What if I guarantee that each element appears only once in a list?


**EDIT:** Guys thanks for the answers but I forgot to add something, the number of occurrences of each element should be the same on both lists.

Compare two List&lt;T&gt; objects for equality, ignoring order

Actually, I&#39;ve found possible solution 

    //returns true
    new BigDecimal(&quot;5.50&quot;).doubleValue() == new BigDecimal(&quot;5.5&quot;).doubleValue()

Of course, it can be improved with something like `Math.abs (v1 - v2) &lt; EPS` to make the comparison more robust, but the question is whether this technique acceptable or is there a better solution?

If someone knows why java designers decided to implement BigDecimal&#39;s equals in that way, it would be interesting to read.

Why BigDecimal(&quot;5.50&quot;) not equals to BigDecimal(&quot;5.5&quot;) and how to work around this issue?

Say I have my own class

    public class MyObj { /* ... */ }

It has some attributes and methods. It DOES NOT implement equals, DOES NOT implement hashCode.

Once we call equals and hashCode, what are the default implementations? From Object class? And what are they? How the default equals will work? How the default hashCode will work and what will return? == will just check if they reference to the same object, so it&#39;s easy, but what about equals() and hashCode() methods?


How default .equals and .hashCode will work for my classes?

I want to check if entity is in a Collection member (`@OneToMany` or `@ManyToMany`) of another entity:

    if (entity2.getEntities1().contains(entity1)) { }



Should I write equals() and hashCode() methods in JPA entities?

What is the difference between `null` and the `&quot;&quot;` (empty string)?

I have written some simple code:

    String a = &quot;&quot;;
    String b = null;
    
    System.out.println(a == b); // false
    System.out.println(a.equals(b)); // false

Both statements return `false`. It seems, I am not able to find what is the actual difference between them.

Difference between null and empty (&quot;&quot;) Java String

I&#39;ve noticed these two interfaces, and several associated classes, have been added in .NET 4. They seem a bit superfluous to me; I&#39;ve read several blogs about them, but I still can&#39;t figure out what problem they solve that was tricky before .NET 4.

What use are `IStructuralEquatable` and `IStructuralComparable`?

What problem does IStructuralEquatable and IStructuralComparable solve?

x and y are two variables.  
I can check if they&#39;re equal using `x == y`, but how can I check if they have the same identity?

Example:

    x = [1, 2, 3]
    y = [1, 2, 3]
Now `x == y` is True because x and y are equal, however, x and y aren&#39;t the same object.  
I&#39;m looking for something like `sameObject(x, y)` which in that case is supposed to be False. 

How do I check if two variables reference the same object in Python?

Assuming dictionary keys and values have their equals and hash methods implemented correctly, what is the most succinct and efficient way to test for equality of two dictionaries?

In this context, two dictionaries are said to be equal if they contain the same set of keys (order not important), and for every such key, they agree on the value.

Here are some ways I came up with (there are probably many more):

    public bool Compare1&lt;TKey, TValue&gt;(
        Dictionary&lt;TKey, TValue&gt; dic1, 
        Dictionary&lt;TKey,TValue&gt; dic2)
    {
        return dic1.OrderBy(x =&gt; x.Key).
            SequenceEqual(dic2.OrderBy(x =&gt; x.Key));
    }

    public bool Compare2&lt;TKey, TValue&gt;(
        Dictionary&lt;TKey, TValue&gt; dic1, 
        Dictionary&lt;TKey, TValue&gt; dic2)
    {
        return (dic1.Count == dic2.Count &amp;&amp; 
            dic1.Intersect(dic2).Count().
            Equals(dic1.Count));
    }

    public bool Compare3&lt;TKey, TValue&gt;(
        Dictionary&lt;TKey, TValue&gt; dic1, 
        Dictionary&lt;TKey, TValue&gt; dic2)
    {
        return (dic1.Intersect(dic2).Count().
            Equals(dic1.Union(dic2).Count()));
    }

Testing for equality between dictionaries in C#

My understanding of these three was:

* `.Equals()` tests for data equality (for the lack of a better description). `.Equals()` can return True for different instances of the same object, and this is the most commonly overridden method.

* `.ReferenceEquals()` tests whether or not two objects are the same instance and cannot be overridden.

* `==` is the same as the `ReferenceEquals()` by default, but this CAN be overridden.

But [C# station][1] states:

&gt; In the object class, the `Equals` and
&gt; `ReferenceEquals` methods are
&gt; semantically equivalent, except that
&gt; the `ReferenceEquals` works only on
&gt; object instances.  The
&gt; `ReferenceEquals` method is static.

Now I don&#39;t get it. Can anyone shed some light on this?

  [1]: http://www.csharp-station.com/Articles/ObjectClass.aspx

Content Type	Original Author	Original Content on Stackoverflow
Question	brianegge	View Question on Stackoverflow
Solution 1 - Bash	schnaader	View Answer on Stackoverflow

bash string equality

Bash Problem Overview

Bash Solutions

Solution 1 - Bash

Measuring text width to be drawn on Canvas ( Android )

Best way to assert for numpy.array equality?

Attributions