Take a look here: [http://longgoldenears.blogspot.com/2007/09/triple-equals-in-javascript.html][1]

The 3 equal signs mean &quot;equality without type coercion&quot;. Using the triple equals, the values must be equal in type as well.

    0 == false   // true
    0 === false  // false, because they are of a different type
    1 == &quot;1&quot;     // true, automatic type conversion for value only
    1 === &quot;1&quot;    // false, because they are of a different type
    null == undefined // true
    null === undefined // false
    &#39;0&#39; == false // true
    &#39;0&#39; === false // false


  [1]: http://longgoldenears.blogspot.com/2007/09/triple-equals-in-javascript.html

`===` and `!==` are strict comparison operators:

&gt; JavaScript has both strict and
&gt; type-converting equality comparison.
&gt; For `strict` equality the objects being
&gt; compared must have the same type and:
&gt; 
&gt; * Two strings are strictly equal when they have the same sequence of
&gt; characters, same length, and same
&gt; characters in corresponding positions.
&gt; * Two numbers are strictly equal when they are numerically equal (have
&gt; the same number value). `NaN` is not
&gt; equal to anything, including `NaN`.
&gt; Positive and negative zeros are equal
&gt; to one another.
&gt; * Two Boolean operands are strictly equal if both are true or
&gt; both are false.
&gt; * Two objects are strictly equal if they refer to the same `Object`.
&gt; * `Null` and `Undefined` types are `==` (but not `===`). [I.e. (`Null==Undefined`) is `true` but (`Null===Undefined`) is `false`]

[Comparison Operators - MDC][1]


  [1]: https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Operators/Comparison_Operators

What&#39;s the simplest way to undo:

    git reset HEAD~

Currently, the only way I can think of is doing a `git clone http://...` from a remote repo.

How to undo &#39;git reset&#39;?

What is the main difference between `StringBuffer` and `StringBuilder`?
Is there any performance issues when deciding on any one of these?

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What is the difference between `==` and `===` in JavaScript?  I have also seen `!=` and `!==` operators.  Are there more such operators?

Difference between == and === in JavaScript

<p>What is the difference between <code>==</code> and <code>===</code> in JavaScript?  I have also seen <code>!=</code> and <code>!==</code> operators.  Are there more such operators?</p>


I&#39;m looking for a way to insert a `&lt;style&gt;` tag into an HTML page with JavaScript.

The best way I found so far:

    var divNode = document.createElement(&quot;div&quot;);
    divNode.innerHTML = &quot;&lt;br&gt;&lt;style&gt;h1 { background: red; }&lt;/style&gt;&quot;;
    document.body.appendChild(divNode);

This works in Firefox, Opera and Internet Explorer but not in Google Chrome. Also it&#39;s a bit ugly with the `&lt;br&gt;` in front for IE.

Does anyone know of a way to create a `&lt;style&gt;` tag that

 1. Is nicer

 2. Works with Chrome?

Or maybe

 1. This is a non-standard thing I should avoid

 2. Three working browsers are great and who uses Chrome anyway?


How to create a &lt;style&gt; tag with Javascript?

I am opening my blog page in my website. The problem is I can give a width to an iframe but the height should be dynamic so that there is no scrollbar in the iframe, and it looks like a single page...

I have tried various JavaScript code to calculate the height of the content but all of them give an *access denied permission* error and is of no use.

    &lt;iframe src=&quot;http://bagtheplanet.blogspot.com/&quot; name=&quot;ifrm&quot; id=&quot;ifrm&quot; width=&quot;1024px&quot; &gt;&lt;/iframe&gt;

Can we use Ajax to calculate height or maybe using PHP?


Resize iframe height according to content height in it

I&#39;m looking for access to financial data from Google services. 

I found [this URL][1] that gets the stock data for Microsoft.

What are all the possible parameters that Google allows for this kind of HTTP request? I&#39;d like to see all the different information that I could get.


  [1]: http://finance.google.com/finance/info?client=ig&amp;q=NASDAQ:MSFT

How can I get stock quotes using Google Finance API?

My company has purchased a product that renders an ASP.NET control on the page. This control uses jQuery 1.2.3 and adds a script tag to the page to reference it. The developers of the control will not support use of the control if it modified in any way (including modification to reference a different version of jQuery).

I&#39;m about to start development of my own control and would like to use the features and speed improvements of jQuery 1.3. Both of these controls will need to exist on the same page.

How can I allow the purchased control to use jQuery 1.2.3 and new custom development to use jQuery 1.3? Also out of curiosity, what if we were to use an additional control that needed to reference yet another version of jQuery?


How do I run different versions of jQuery on the same page?

I am toying around with a pretty intensive ajax based jquery web application. It is getting to a point where I almost loose track of what events that should trigger what actions etc.

I am sort of left with a feeling that my javascript structure is wrong, on a more basic level. How do you guys structure your javascript/jquery code, the event handling etc., any advise for a newbie javascript developer.

How to structure my javascript/jquery code?

What is the Ruby `&lt;=&gt;` (spaceship) operator? Is the operator implemented by any other languages?

What is the Ruby &lt;=&gt; (spaceship) operator?

I&#39;ve noticed someone using the PHP operator `===` which I can&#39;t make sense out of. I&#39;ve tried it with a function, and it corresponds in crazy ways.

What is the definition of this operator? I can&#39;t even find it in the declaration of PHP operators.


What does &quot;===&quot; mean?

How to select a result of comparison operator as a field with type BIT?

How it does work in `C#`:

    bool isGreater = FieldA &gt; FieldB;

How it doesn&#39;t work in `T-SQL`:

    SELECT (FieldA &gt; FieldB) AS BIT FROM t

How to write such task properly?

Using comparison operators in SELECT clause of T-SQL query

Why is === faster than == in PHP?

I&#39;m trying to compare two numbers in R as a part of a if-statement condition:

`(a-b) &gt;= 0.5`

In this particular instance, a = 0.58 and b = 0.08... and yet `(a-b) &gt;= 0.5` is false.  I&#39;m aware of the dangers of using `==` for exact number comparisons, and this seems related:

`(a - b) == 0.5)` is false, while 

`all.equal((a - b), 0.5)` is true.

The only solution I can think of is to have two conditions: `(a-b) &gt; 0.5 | all.equal((a-b), 0.5)`.  This works, but is that really the only solution?  Should I just swear off of the `=` family of comparison operators forever?


**Edit for clarity:** I know that this is a floating point problem.  More fundamentally, what I&#39;m asking is: what should I do about it?  What&#39;s a sensible way to deal with greater-than-or-equal-to comparisons in R, since the `&gt;=` can&#39;t really be trusted?

Numeric comparison difficulty in R

For my unittest, I want to check if two arrays are identical.  Reduced example: 

    a = np.array([1, 2, np.NaN])
    b = np.array([1, 2, np.NaN])

    if np.all(a==b):
        print &#39;arrays are equal&#39;

This does not work because `nan != nan`.
What is the best way to proceed?

Comparing numpy arrays containing NaN

Why does the following statement return false in JavaScript?

    new String(&#39;hello&#39;) === new String(&#39;hello&#39;)

Why does new String(&#39;hello&#39;) === new String(&#39;hello&#39;) evaluate to False?

I&#39;m learning about operator overloading in C++, and I see that `==` and `!=` are simply some special functions which can be customized for user-defined types. My concern is, though, why are there *two separate* definitions needed? I thought that if `a == b` is true, then `a != b` is automatically false, and vice versa, and there is no other possibility, because, by definition, `a != b` is `!(a == b)`. And I couldn&#39;t imagine any situation in which this wasn&#39;t true. But perhaps my imagination is limited or I am ignorant of something?

I know that I can define one in terms of the other, but this is not what I&#39;m asking about. I&#39;m also not asking about the distinction between comparing objects by value or by identity. Or whether two objects could be equal and non-equal at the same time (this is definitely not an option! these things are mutually exclusive). What I&#39;m asking about is this:

Is there any situation possible in which asking questions about two objects being equal does make sense, but asking about them *not* being equal doesn&#39;t make sense? (either from the user&#39;s perspective, or the implementer&#39;s perspective)

If there is no such possibility, then why on Earth does C++ have these two operators being defined as two distinct functions?

Are == and != mutually dependent?

According to [cppreference](https://en.cppreference.com/w/cpp/types/type_info/operator_cmp), `std::type_info::operator!=` gets removed with C++20, however, `std::type_info::operator==` apparently remains.

What&#39;s the reasoning behind? I might agree on comparing for inequality being meaningless, but then comparing for equality would be just as meaningless as well, wouldn&#39;t it?

Similarly, `operator!=` of many other standard library types, including containers such as [`std::unordered_map::operator!=`][2] and [`std::unordered_set::operator!=`][3] will be removed in C++20 according to cppreference.

Having to write `if(!(id1 == id2))` doesn&#39;t make any code any clearer compared to `if(id1 != id2)`, in contrast, just the opposite...

[2]: https://en.cppreference.com/w/cpp/container/unordered_map/operator_cmp
[3]: https://en.cppreference.com/w/cpp/container/unordered_set/operator_cmp

Content Type	Original Author	Original Content on Stackoverflow
Question	Shiva	View Question on Stackoverflow
Solution 1 - Javascript	sdfx	View Answer on Stackoverflow
Solution 2 - Javascript	Jack Sleight	View Answer on Stackoverflow

Difference between == and === in JavaScript

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