The expressions `0.0` and `00.0` are parsed differently.

- `0.0` is parsed as a numeric literal &lt;sup&gt;1&lt;/sup&gt;
- `00.0` is parsed as:
  - `00` – octal numeric literal &lt;sup&gt;2&lt;/sup&gt;
  - `.` – property accessor
  - `0` – identifier name

Your code throws syntax error because `0` is not a valid JavaScript identifier. The following example works since `toString` is a valid identifier:


    00.toString


&lt;sup&gt;1&lt;/sup&gt; [Section 7.8.3][1] – Leading 0 can be followed by *decimal separator* or *ExponentPart*  
&lt;sup&gt;2&lt;/sup&gt; [Section B.1.1][2] – Leading 0 can be followed by *OctalDigits*


  [1]: http://www.ecma-international.org/ecma-262/5.1/#sec-7.8.3
  [2]: http://www.ecma-international.org/ecma-262/5.1/#sec-B.1.1

`00` is evaluated as an octal number and `.0` is evaluated as accessing that number&#39;s property. But since integers are not allowed to be used as property accessors, the error is thrown.

You get the same error for any other object:

    &#39;string&#39;.0 // Syntax error: unexpected number
    ({}).0 // Syntax error: unexpected number

You can find related information about property accessors on [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Property_Accessors).

I am working on Google oauthorization2 and I encounter problem that 
&gt;SQL dialect is not configured 

That&#39;s why my query is not executing and data is going to table.

I have listed below both of queries where I encounter problem.

Tools:
PhpStorm 8+
MySQL
Localhost 


    $user_exist = $mysqli-&gt;query(&quot;SELECT COUNT(google_id) as usercount FROM google_users WHERE google_id=$user_id&quot;)-&gt;fetch_object()-&gt;usercount;
    
    $mysqli-&gt;query(&quot;INSERT INTO google_users (google_id, google_name, google_email, google_link, google_picture_link)
    		VALUES ($user_id, &#39;$user_name&#39;,&#39;$email&#39;,&#39;$profile_url&#39;,&#39;$profile_image_url&#39;)&quot;);



SQL Dialect is Not Configured (Phpstorm)

I know a little about Linux. Today I created a [VPN][1] server on my Ubuntu installation according to *[Set up a simple IPsec/L2TP VPN server for Ubuntu, Arch Linux and Debian][2]*.

But when I finish the installation, I use my iPhone to connect the [IPsec][3] VPN, bur it shows the VPN Server has no response.

The GitHub document shows

&gt; Ports 1701, 500 and 4500 must be opened for the VPN to work!

So I have tried to open these ports on my Ubuntu server.

I use the [iptables][4] command to open these ports, but it failed. Maybe I don&#39;t known how to use this command correctly. How can I open these ports on my Ubuntu server?

And if these ports have been opened successfully, can it be proved by the Windows [CMD][5] window through [telnet][6]&#39;ting the port?


  [1]: https://en.wikipedia.org/wiki/Virtual_private_network
  [2]: https://github.com/philplckthun/setup-simple-ipsec-l2tp-vpn
  [3]: https://en.wikipedia.org/wiki/IPsec
  [4]: https://en.wikipedia.org/wiki/Iptables
  [5]: https://en.wikipedia.org/wiki/Cmd.exe
  [6]: https://en.wikipedia.org/wiki/Telnet







How can I open some ports on Ubuntu?

This is weird.  This is what happens at the JavaScript console in Chrome (version 42.0.2311.135, 64-bit).

&lt;!-- language: lang-none --&gt;

    &gt; 0
    &lt; 0
    &gt; 00
    &lt; 0
    &gt; 0.0
    &lt; 0
    &gt; 00.0
    X Uncaught &gt; SyntaxError: Unexpected number

Firefox 37.0.2 does the same, although its error message is:

&lt;!-- language: lang-none --&gt;

    SyntaxError: missing ; before statement

There&#39;s probably some technical explanation regarding the way JavaScript parses numbers, and perhaps it can only happen when tinkering at the console prompt, but it still seems wrong.

Why does it do that?


Why does 00.0 cause a syntax error?

This is weird. This is what happens at the JavaScript console in Chrome (version 42.0.2311.135, 64-bit).

<pre><code class="hljs language-markdown">> 0
&#x3C; 0
> 00
&#x3C; 0
> 0.0
&#x3C; 0
> 00.0
X Uncaught > SyntaxError: Unexpected number
</code></pre>
Firefox 37.0.2 does the same, although its error message is:

<pre><code class="hljs language-css">SyntaxError: missing ; before statement
</code></pre>
There's probably some technical explanation regarding the way JavaScript parses numbers, and perhaps it can only happen when tinkering at the console prompt, but it still seems wrong.
Why does it do that?

I am playing around with the ReactJS framework on [JSBin](https://jsbin.com/).

I have noticed that if my component name starts with a lowercase letter it does not work.

For instance the following does not render:


    var fml = React.createClass({
      render: function () {
        return &lt;a href=&#39;google.com&#39;&gt;Go&lt;/a&gt;
      }
    });
    
    React.render(&lt;fml /&gt;, document.body);



But as soon as I replace the `fml` with `Fml` it does render. 

Is there a reason I cannot begin tags with small letters?

ReactJS component names must begin with capital letters?

In AngularJs `ng-enabled` directive is not provided. Is there any proper reason to not providing that directive in the framework, because we are having both `ng-show` and `ng-hide` when you can just use `ng-hide` to achieve our goal.

It wouldn&#39;t be nice just to check 
    **`ng-enabled=&quot;attribute.value === true&quot;`**

instead of
    **`ng-disabled=&quot;!(attribute.value === true)&quot;`** 

it will increase the readability of the code.

In angularjs we are having ng-disabled directive, why ng-enabled directive is not provided by the framework as we are having ng-show and ng-hide

When deploying my Rails app I get the following error:

    rake aborted!
       ExecJS::ProgramError: Unexpected token punc &#171;(&#187;, expected punc &#171;:&#187; (line: 15, col: 14, pos: 265)
       
       Error
       at new JS_Parse_Error (/tmp/execjs20150524-4411-1p45n63js:2359:10623)
       at js_error (/tmp/execjs20150524-4411-1p45n63js:2359:10842)
       at croak (/tmp/execjs20150524-4411-1p45n63js:2359:19086)
       at token_error (/tmp/execjs20150524-4411-1p45n63js:2359:19223)
       at expect_token (/tmp/execjs20150524-4411-1p45n63js:2359:19446)
       at expect (/tmp/execjs20150524-4411-1p45n63js:2359:19584)
       at /tmp/execjs20150524-4411-1p45n63js:2359:28513
       at /tmp/execjs20150524-4411-1p45n63js:2359:19957
       at expr_atom (/tmp/execjs20150524-4411-1p45n63js:2359:27269)
       at maybe_unary (/tmp/execjs20150524-4411-1p45n63js:2359:30019)new JS_Parse_Error ((execjs):2359:10623)
       js_error ((execjs):2359:10842)
       croak ((execjs):2359:19086)
       token_error ((execjs):2359:19223)
       expect_token ((execjs):2359:19446)
       expect ((execjs):2359:19584)
       (execjs):2359:28513
       (execjs):2359:19957
       expr_atom ((execjs):2359:27269)
       maybe_unary ((execjs):2359:30019)

The file in question is valid, it works on localhost. I also tried running `rake assests:precompile` on localhost, it all passes. Finally, I tried to remove the content from the file, git push and redeploy - still got the same error. Only completely removing the file and re-deploying helps.

Would appreciate any ideas.

ExecJS::ProgramError: Unexpected token punc &#171;(&#187;, expected punc &#171;:&#187; when running rake assets:precompile on production

After learning about [Observables](https://github.com/jhusain/asyncgenerator), I find them quite similar to [Node.js streams][1]. Both have a mechanism of notifying the consumer whenever new data arrives, an error occurs or there is no more data (EOF).

I would love to learn about the conceptual/functional differences between the two. Thanks!


  [1]: https://nodejs.org/api/stream.html

Node.js Streams vs. Observables

Can I use inline HTML in a script as below by using a library like jsx:
    
    &lt;script src=&quot;jsx-transform.js&quot;&gt;&lt;/script&gt;
    &lt;script type=&quot;text/jsx&quot;&gt;
    define(&#39;component&#39;, function () {
       return (&lt;div&gt;test html code&lt;/div&gt;);
    });
    &lt;/script&gt;

Can I use jsx without React to inline HTML in script?

Is it possible to get a random number between 1-100 and keep the results mainly within the 40-60 range? I mean, it will go out of that range rarely, but I want it to be mainly within that range... Is it possible with JavaScript/jQuery?

Right now I&#39;m just using the basic `Math.random() * 100 + 1`.


Get a random number focused on center

I want to restrict user input to positive numbers in an html form. 

I know you can set min=&quot;0&quot;, however it is possible to bypass this by manually entering a negative number. 

Is there any other way to solve this without writing a validation function?

Prevent negative inputs in form input type=&quot;number&quot;?

I have the following html5 input element:

    &lt;input type=&quot;number&quot;&gt;

Why does this input allow for the character &#39;e&#39; to be entered in the input field? No other alphabet character is able to be entered (as expected)

Using chrome v. 44.0.2403.107

Example below to see what I mean. 

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-html --&gt;

    &lt;input type=&quot;number&quot;&gt;

&lt;!-- end snippet --&gt;



Why does the html input with type &quot;number&quot; allow the letter &#39;e&#39; to be entered in the field?

I have a confusion in how NaN works. I have executed `isNaN(undefined)` it returned `true` . But if I will use `Number.isNaN(undefined)` it is returning `false`. So which one i should use. Also why there is so discrepancy in the result.

Confusion between isNaN and Number.isNaN in javascript

I have a `&lt;input type=&quot;number&quot;&gt;` and I want to restrict the input of the users to purely numbers or numbers with decimals up to 2 decimal places.

Basically, I am asking for a price input.

I wanted to avoid doing regex. Is there a way to do it?

    &lt;input type=&quot;number&quot; required name=&quot;price&quot; min=&quot;0&quot; value=&quot;0&quot; step=&quot;any&quot;&gt;

Allow 2 decimal places in &lt;input type=&quot;number&quot;&gt;

I have an HTML file :

    &lt;!DOCTYPE HTML&gt;
    &lt;html lang=&quot;en-US&quot; ng-app=&quot;Todo&quot;&gt;
    &lt;head&gt;
    	&lt;meta charset=&quot;UTF-8&quot;&gt;
    	&lt;title&gt;DemoAPI&lt;/title&gt;
    		
      &lt;meta name=&quot;viewport&quot;&gt;
      
    &lt;link rel=&quot;stylesheet&quot; href=&quot;http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css&quot;&gt;
    &lt;script src=&quot;http://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js&quot;&gt;&lt;/script&gt;
    &lt;script type=&quot;text/javascript&quot; src=&quot;https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.4/jquery.js&quot;&gt;&lt;/script&gt;
    
    &lt;link rel=&quot;stylesheet&quot; href=&quot;./Client/css/styling.css&quot; /&gt;
    &lt;script type=&quot;text/javascript&quot; src=&quot;core.js&quot;&gt;&lt;/script&gt;
    
    &lt;/head&gt;

The error says:


    Uncaught SyntaxError: Unexpected token &lt;    core.js: 1
    

It shows the error at `&lt;!doctype html&gt;` of the `app.html`.

`core.js` looks like this:

    angular.module(&#39;Todo&#39;, [])
    
    .controller(&#39;mainController&#39;, function($scope, $http)
    {
        $scope.formData = {};
    
        // get all and show them
        $http.get(&#39;/musicians&#39;)
            .success(function(data) {
                $scope.todos = data;
                console.log(data);
            })
            .error(function(data) {
                console.log(&#39;Error: &#39; + data);
            });
    
    		//get with an id
    		$scope.getOneTodo = function() {
            $http.get(&#39;/musicians&#39; + id)
                .success(function(data) {
                    $scope.todos = data;
    				      console.log(data);
                })
                .error(function(data) {
                    console.log(&#39;Error: &#39; + data);
                });
        };
          // send the text to the node API
        $scope.createTodo = function() {
            $http.post(&#39;/musicians&#39;, $scope.formData)
                .success(function(data) {
                    $scope.formData = {}; // clear the form 
                    $scope.todos = data;
                    console.log(data);
                })
                .error(function(data) {
                    console.log(&#39;Error: &#39; + data);
                })
        };
    
        // delete 
        $scope.deleteTodo = function(id) {
            $http.delete(&#39;/musicians&#39; + id)
                .success(function(data) {
                    $scope.todos = data;
    				      console.log(data);
                })
                .error(function(data) {
                    console.log(&#39;Error: &#39; + data);
                });
        };
    	
    	/*
    	$scope.updateTodo = function(id) {
            $http.delete(&#39;/musicians&#39; + id)
                .success(function(data) {
                    $scope.todos = data;
    				      console.log(data);
                })
                .error(function(data) {
                    console.log(&#39;Error: &#39; + data);
                });
        };*/
    
    });

It also gives me `Uncaught Error: [$injector:modulerr] http://errors.angularjs.org/1.3.14/$injector/modulerr?p0=Todo&amp;p1=Error%3A%2…gleapis.com%2Fajax%2Flibs%2Fangularjs%2F1.3.14%2Fangular.min.js%3A17%3A381)`

Besides, in console, when I click at `core.js`, it shows the contents of `app.html` and name it `core.js`.

Here is the snapshot:

![Showing app.html instead of core.js][1]


Also, as in the image, when I click `index.html`, it shows `app.html`. However, I do not have any file that is named `index.html` and I load `app.html` by default instead of `index.html`.

I have tried adding/removing `type=&quot;text/javascript&quot;` but no help with that either.

Also, status 200 is returned on get request for `core.js`.

![Status: 200][2]

What might be wrong?


  [1]: http://i.stack.imgur.com/vGytf.png
  [2]: http://i.stack.imgur.com/DxCy8.png

Unexpected token &lt; in first line of HTML

The solutions offered in other related questions, such as including the proper presets (es2015) in .babelrc, are already implemented in my project.

I have two projects (lets call them A and B) which both use ES6 module syntax.  In Project A, I&#39;m importing Project B which is installed via npm and lives in the node_modules folder. When I run my test suite for Project A, I&#39;m getting the error: 

&gt; SyntaxError: Unexpected token import

Which is preceded by this alleged erroneous line of code from Project B:
 

&gt; (function (exports, require, module, __filename, __dirname) { import
&gt; createBrowserHistory from &#39;history/lib/createBrowserHistory&#39;;

The iife appears to be something npm or possibly babel related since my source file only contains &quot;import createBrowserHistory from &#39;history/lib/createBrowserHistory&#39;; The unit tests in Project B&#39;s test suite runs fine, and if I remove Project B as a dependency from Project A, my test suite then (still using es6 imports for internal project modules) works just fine.

Full Stack Trace:

     SyntaxError: Unexpected token import
        at exports.runInThisContext (vm.js:53:16)
        at Module._compile (module.js:374:25)
        at Module._extensions..js (module.js:405:10)
        at Object.require.extensions.(anonymous function) [as .js] (/ProjectA/node_modules/babel-register/lib/node.js:138:7)
        at Module.load (module.js:344:32)
        at Function.Module._load (module.js:301:12)
        at Module.require (module.js:354:17)
        at require (internal/module.js:12:17)
        at Object.&lt;anonymous&gt; (actionCreators.js:4:17)
        at Module._compile (module.js:398:26)
        at loader (/ProjectA/node_modules/babel-register/lib/node.js:130:5)
        at Object.require.extensions.(anonymous function) [as .js] (/ProjectA/node_modules/babel-register/lib/node.js:140:7)
        at Module.load (module.js:344:32)
        at Function.Module._load (module.js:301:12)
        at Module.require (module.js:354:17)
        at require (internal/module.js:12:17)
        at Object.&lt;anonymous&gt; (/ProjectA/src/components/core/wrapper/wrapper.js:28:23)
        at Module._compile (module.js:398:26)
        at loader (/ProjectA/node_modules/babel-register/lib/node.js:130:5)
        at Object.require.extensions.(anonymous function) [as .js] (/ProjectA/node_modules/babel-register/lib/node.js:140:7)
        at Module.load (module.js:344:32)
        at Function.Module._load (module.js:301:12)
        at Module.require (module.js:354:17)
        at require (internal/module.js:12:17)
        at Object.&lt;anonymous&gt; (/ProjectA/src/components/core/wrapper/wrapperSpec.js:15:16)
        at Module._compile (module.js:398:26)
        at loader (/ProjectA/node_modules/babel-register/lib/node.js:130:5)
        at Object.require.extensions.(anonymous function) [as .js] (/ProjectA/node_modules/babel-register/lib/node.js:140:7)
        at Module.load (module.js:344:32)
        at Function.Module._load (module.js:301:12)
        at Module.require (module.js:354:17)
        at require (internal/module.js:12:17)
        at /ProjectA/node_modules/mocha/lib/mocha.js:219:27
        at Array.forEach (native)
        at Mocha.loadFiles (/ProjectA/node_modules/mocha/lib/mocha.js:216:14)
        at Mocha.run (/ProjectA/node_modules/mocha/lib/mocha.js:468:10)
        at Object.&lt;anonymous&gt; (/ProjectA/node_modules/mocha/bin/_mocha:403:18)
        at Module._compile (module.js:398:26)
        at Object.Module._extensions..js (module.js:405:10)
        at Module.load (module.js:344:32)
        at Function.Module._load (module.js:301:12)
        at Function.Module.runMain (module.js:430:10)
        at startup (node.js:141:18)
        at node.js:980:3

Here is my test command from package.json:

    &quot;test&quot;: &quot;mocha --compilers js:babel-core/register &#39;+(test|src)/**/*Spec.js&#39;&quot;

This StackOverflow post is similar but doesn&#39;t offer a solution for my use of the command line:
https://stackoverflow.com/questions/31822593/import-a-module-from-node-modules-with-babel-but-failed

Babel unexpected token import when running mocha tests

I know that semicolons are unnecessary in Python, but they can be used to cram multiple statements onto a single line, e.g.

&lt;!-- language: none --&gt;

    &gt;&gt;&gt; x = 42; y = 54

I always thought that a semicolon was equivalent to a line break. So I was a bit surprised to learn (h/t [Ned Batchelder on Twitter](https://twitter.com/nedbat/status/709326204051005440)) that a double semicolon is a SyntaxError:

&lt;!-- language: none --&gt;

    &gt;&gt;&gt; x = 42
    &gt;&gt;&gt; x = 42;
    &gt;&gt;&gt; x = 42;;
      File &quot;&lt;stdin&gt;&quot;, line 1
        x = 42;;
               ^
    SyntaxError: invalid syntax

&lt;/p&gt;

I assumed the last program was equivalent to `x = 42\n\n`. I’d have thought the statement between the semicolons was treated as an empty line, a no-op. Apparently not.

**Why is this an error?**

Why is a double semicolon a SyntaxError in Python?

I&#39;m trying to read a .csv file into Python (Spyder) but I keep getting an error. My code:

	import csv

	data = open(&quot;C:\Users\miche\Documents\school\jaar2\MIK\2.6\vektis_agb_zorgverlener&quot;)
	data = csv.reader(data)  
	print(data)

I get the following error:

&gt; SyntaxError: (unicode error) &#39;unicodeescape&#39; codec can&#39;t decode bytes
&gt; in position 2-3: truncated \UXXXXXXXX escape

I have tried to replace the \ with \\ or with / and I&#39;ve tried to put an r before *&quot;C..* but all these things didn&#39;t work.

(unicode error) &#39;unicodeescape&#39; codec can&#39;t decode bytes in position 2-3: truncated \UXXXXXXXX escape

I&#39;m following the Django tutorial https://docs.djangoproject.com/es/1.10/intro/tutorial01/ 

I&#39;ve created a &quot;mysite&quot; dummy project (my very first one) and try to test it without altering it.


    django-admin startproject mysite
    cd mysite
    python manage.py runserver
    
    File &quot;manage.py&quot;, line 14
    ) from exc
    ^
    SyntaxError: invalid syntax

I&#39;m getting a SyntaxError on a file that was generated by the system itself. And I seem unable to find anyone else who has gone through the same issue.

I&#39;ll add some data of my setup in case it may be of use


    $ vpython --version
    Python 2.7.12
    $ pip --version
    pip 9.0.1 from /home/frank/.local/lib/python2.7/site-packages (python 2.7)
    $ python -m django --version
    1.10.6




 Adding contents of autogenerated manage.py

    cat manage.py 
    #!/usr/bin/env python3
    import os
    import sys
    
    if __name__ == &quot;__main__&quot;:
        os.environ.setdefault(&quot;DJANGO_SETTINGS_MODULE&quot;, &quot;mysite.settings&quot;)
        try:
            from django.core.management import execute_from_command_line
        except ImportError as exc:
            raise ImportError(
                &quot;Couldn&#39;t import Django. Are you sure it&#39;s installed and &quot;
                &quot;available on your PYTHONPATH environment variable? Did you &quot;
                &quot;forget to activate a virtual environment?&quot;
            ) from exc
        execute_from_command_line(sys.argv)


Content Type	Original Author	Original Content on Stackoverflow
Question	Chris Dennis	View Question on Stackoverflow
Solution 1 - Javascript	Salman A	View Answer on Stackoverflow
Solution 2 - Javascript	Robert Rossmann	View Answer on Stackoverflow

Why does 00.0 cause a syntax error?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

How can I open some ports on Ubuntu?

SQL Dialect is Not Configured (Phpstorm)

Attributions