The dot operator `.` does not need to be escaped inside of a character class `[]`.

Because the dot is inside character class (square brackets `[]`).

Take a look at http://www.regular-expressions.info/reference.html, it says (under char class section):

&gt; Any character except ^-]\ add that character to the possible matches
&gt; for the character class.



If you using JavaScript to test your Regex, try `\\.` instead of `\.`.

It acts on the same way because JS remove first backslash.

On [this web page](http://www.regular-expressions.info/dot.html), I see that:

&quot;Remember that the dot is not a metacharacter inside a character class, so we do not need to escape it with a backslash.&quot;

So I guess the escaping of it is unnecessary...

Is it possible to have a socket.io client respond to all events without to have specify each event individually?

For example, something like this (which obviously doesn&#39;t work right now):

&lt;pre&gt;&lt;code&gt;var socket = io.connect(&quot;http://myserver&quot;);

socket.on(&quot;*&quot;, function(){
  // listen to any and all events that are emitted from the
  // socket.io back-end server, and handle them here.

  // is this possible? how can i do this?
});
&lt;/code&gt;&lt;/pre&gt;

I want this callback function to be called when any / all events are received by the client-side socket.io code.

Is this possible? How?

Socket.io Client: respond to all events with one handler?

For some reason I&#39;m never able to use external libraries in any language. I&#39;m looking for instructions/explanations of how to use external libraries, as well as how they work. When I search online, I get fragments that never seem to apply to whatever library I download and try and use. I work on both a mac and a pc, and C++ examples are fine. I use eclipse IDE with the C++ plug in. If there are instructions that apply to all libraries that would be great. 

How to use Libraries

For some reason those two regex act the same way:

    &quot;43\\gf..--.65&quot;.replace(/[^\d.-]/g, &quot;&quot;);​  // 43..--.65
    &quot;43\\gf..--.65&quot;.replace(/[^\d\.-]/g, &quot;&quot;);​  // 43..--.65
[Demo][1]

In the first regex I don&#39;t escape the dot(`.`) while in the second regex I do(`\.`).

What are the differences and why they act the same? 


  [1]: http://jsfiddle.net/q7rvt/1/

Escape dot in a regex range

For some reason those two regex act the same way:
<pre><code class="hljs language-javascript">"43\\gf..--.65".replace(/[^\d.-]/g, "");​ // 43..--.65
"43\\gf..--.65".replace(/[^\d\.-]/g, "");​ // 43..--.65
</code></pre>
<a href="http://jsfiddle.net/q7rvt/1/" target="_blank" rel="noopener noreferrer">Demo</a>
In the first regex I don't escape the dot(<code>.</code>) while in the second regex I do(<code>\.</code>).
What are the differences and why they act the same?

I&#39;ve got a `data-123` string.

How can I remove `data-` from the string while leaving the `123`?

How to remove text from a string?

I have a Handlebars template where I&#39;m trying to generate a comma-separated list of items from an array.

In my Handlebars template:

    {{#each list}}
        {{name}} {{status}},
    {{/each}}

I want the `,` to not show up on the last item.  Is there a way to do this in Handlebars or do I need to fall back to CSS selectors?

**UPDATE**: Based on Christopher&#39;s suggestion, this is what I ended up implementing:

    var attachments = Ember.CollectionView.extend({
        content: [],
        itemViewClass: Ember.View.extend({
            templateName: &#39;attachments&#39;,
            tagName: &#39;span&#39;,
            isLastItem: function() {
                return this.getPath(&#39;parentView.content.lastObject&#39;) == this.get(&#39;content&#39;);
            }.property(&#39;parentView.content.lastObject&#39;).cacheable()
        })
    }));

and in my view:

    {{collection attachments}}

and the item view:

    {{content.title}} ({{content.size}}) {{#unless isLastItem}}, {{/unless}}



How do I add a separator between elements in an {{#each}} loop except after the last element?

I cannot find the JavaScript equivalent of PHP `array_keys()` / `array_values()`.

For people unfamiliar with PHP given the following JavaScript hash:

    var myHash = {&quot;apples&quot;: 3, &quot;oranges&quot;: 4, &quot;bananas&quot;: 42}

How can I get an array of keys, i.e.,

    [&quot;apples&quot;, &quot;oranges&quot;, &quot;bananas&quot;]

The same question with the values, i.e.,

    [3, 4, 42]

jQuery can be used.





Hash keys / values as array

I am using the excellent [Underscore.js][1] library. I have a specific task which I can do fine using JavaScript or jQuery but was wondering if there was some sort of abstraction avaialable in Underscore that I was missing out on.

Essentially I have an object like so - 

    var some_object_array = [{id: &quot;a&quot;, val: 55}, {id: &quot;b&quot;, val: 1}, {id: &quot;c&quot;, val: 45}];

I want to convert this into -

    var some_map = {&quot;a&quot;: {id: &quot;a&quot;, val: 55}, &quot;b&quot;: {id: &quot;b&quot;, val: 1}, &quot;c&quot;: {id: &quot;c&quot;, val: 45}};

I know that I can use `_.groupBy(some_object_array, &quot;id&quot;)`. But this returns a map like so -

    var some_grouped_map = {&quot;a&quot;: [{id: &quot;a&quot;, val: 55}], &quot;b&quot;: [{id: &quot;b&quot;, val: 1}], &quot;c&quot;: [{id: &quot;c&quot;, val: 45}]};

Note that this does what it is advertised to do. But I was hoping to get `some_map` without iterating over the objects myself.

Any help appreciated.


  [1]: http://underscorejs.org/

Underscore.js: create a map out of list of objects using a key found in the object

I am passing a list of regex patterns to `grep` to check against a syslog file. They are usually matching an IP address and log entry;

    grep &quot;1\.2\.3\.4.*Has exploded&quot; syslog.log

It&#39;s just a list of patterns like the `&quot;1\.2\.3\.4.*Has exploded&quot;` part I am passing, in a loop, so I can&#39;t pass &quot;-v&quot; for example.

I am confused trying to do the inverse of the above, and NOT match lines with a certain IP address and error so &quot;\!1\.2\.3\.4.*Has exploded&quot; will match syslog lines for anything other than 1.2.3.4 telling me it has exploded. I **must** be able to include an IP to NOT match.

I have seen various similar posts on StackOverflow. However they use regex patterns that I can&#39;t seem to get to work with `grep`. Can anyone provide a working example for `grep` please?

**UPDATE:**
This is happening in a script like this;

    patterns[1]=&quot;1\.2\.3\.4.*Has exploded&quot;
    patterns[2]=&quot;5\.6\.7\.8.*Has died&quot;
    patterns[3]=&quot;\!9\.10\.11\.12.*Has exploded&quot;
    
    for i in {1..3}
    do
     grep &quot;${patterns[$i]}&quot; logfile.log
    done

Grep regex NOT containing string

I am writing a Java app to export data from Oracle to csv file

Unfortunately the content of data may quite tricky. Still comma is the deliminator, but some data on a row could be like this:

    | ID    |   FN    |   LN   |  AGE   |  COMMENT                   |
    |----------------------------------------------------------------|
    | 123   |  John   |  Smith |   39   | I said &quot;Hey, I am 5&#39;10&quot;.&quot;  |
    |----------------------------------------------------------------|

so this is one of the string on the `comment` column:

&gt;I said &quot;Hey, I am 5&#39;10&quot;.&quot;

No kidding, I need to show above comment without compromise in excel or open office from a CSV file generated by Java, and of course cannot mess up other regular escaping situation(i.e. regular double quotes, and regular comma within a tuple). I know regular expression is powerful but how can we achieve the goal with such complicated situation?


How to escape comma and double quote at same time for CSV file?

I need a regular expression to validate image file extensions in javascript. Do you have one ?

Regex JavaScript image file extension

The regex `/abc$/` will match an `abc` that does appear at the end of the line. How do I do the inverse?

I want to match `abc` that isn&#39;t at the end of a line.

Furthermore, I&#39;m going to be using the regex to replace strings, so I want to capture only `abc`, not anything after the string, so `/abc.+$/` doesn&#39;t work, because it would replace not only `abc` but anything after `abc` too.

What is the correct regex to use?


What is a regex to match a string NOT at the end of a line?

So essentially I&#39;m looking for specifically a 4 digit code within two angle brackets within a text file. I know that I need to open the text file and then parse line by line, but I am not sure the best way to go about structuring my code after checking &quot;for line in file&quot;. 

I think I can either somehow split it, strip it, or partition, but I also wrote a regex which I used compile on and so if that returns a match object I don&#39;t think I can use that with those string based operations. Also I&#39;m not sure whether my regex is greedy enough or not...

I&#39;d like to store all instances of those found hits as strings within either a tuple or a list. 

Here is my regex: 

    regex = re.compile(&quot;(&lt;(\d{4,5})&gt;)?&quot;)

I don&#39;t think I need to include all that much code considering its fairly basic so far. 

How do I search for a pattern within a text file using Python combining regex &amp; string/file operations and store instances of the pattern?

I have a string with multiple commas, and the string replace method will only change the first one:

    var mystring = &quot;this,is,a,test&quot;
    mystring.replace(&quot;,&quot;,&quot;newchar&quot;, -1)

**Result**: `&quot;thisnewcharis,a,test&quot;`

The documentation indicates that the default replaces all, and that &quot;-1&quot; also indicates to replace all, but it is unsuccessful. Any thoughts?

JavaScript - Replace all commas in a string

This might appear to be a dupe, but rest assured it isn&#39;t - I have searched both SO as well as the rest of the web for an answer to my problem and ended up finding the same insufficient &quot;solutions&quot; over and over. Anyhow, here it goes:

I&#39;m saving user input from a textarea to a MySQL database (within a WordPress environment, but that ought not to matter to this problem, I believe). It is later retrieved from the DB to be shown to Admins in the backend of the site. The problem occurs when users submit text with line breaks (i.e. hit the Enter key).

A sample string might look like this:

    Dear friends, I just wanted so Hello. How are you guys? I&#39;m fine, thanks!

    Greetings,
    Bill

There are no end of line characters (&quot;\n&quot;, &quot;\r&quot;, or the like) in the string.

I am using `nl2br()` on it to generate HTML output, but that&#39;s not enough. The result then is:

    Dear friends, I just wanted so Hello. How are you guys? I&#39;m fine, thanks!&lt;br /&gt;
    &lt;br /&gt;
    Greetings,&lt;br /&gt;
    Bill

Which, as far as I understand it, is the expected `nl2br()` result, as that inserts the tags and isn&#39;t supposed to replace the line-breaks in the first place?

However the format I need would be this:

    Dear friends, I just wanted so Hello. How are you guys? I&#39;m fine, thanks!&lt;br /&gt;&lt;br /&gt;Greetings,&lt;br /&gt;Bill

If the string had EOL characters such as &quot;\n&quot; in it, I&#39;d hit it with either `str_replace()` or `preg_replace()` and be done with it, but I have no clue what needle to feed either of those functions if there ain&#39;t no characters there in the first place.

I can manually access the relevant field in the DB, hit Backspace for every linebreak and what I later on want to do with the string works. So I know I need the above format.

How to remove line breaks (no characters!) from the string?

What&#39;s the difference between java.lang.String &#39;s `replace()` and `replaceAll()` methods, 
other than later uses regex? For simple substitutions like, replace `.` with `/`  , 
is there any difference?

Difference between String replace() and replaceAll()

I want to replace first occurrence of String in the following.

      String test = &quot;see Comments, this is for some test, help us&quot;
  
   **If test contains the input as follows it should not replace

   1. See Comments, (with space at the end)
   2. See comments,
   3. See Comments**

I want to get the output as follows,

     Output: this is for some test, help us


Thanks in advance,


How to replace first occurrence of string in Java

I have a situation where I want a bash script to replace an entire line in a file.
The line number is always the same, so that can be a hard-coded variable.

I&#39;m not trying to replace some sub-string in that line, I just want to replace that line entirely with a new line.

Are there any bash methods for doing this (or something simple that can be thrown into a .sh script).

Content Type	Original Author	Original Content on Stackoverflow
Question	gdoron is supporting Monica	View Question on Stackoverflow
Solution 1 - Javascript	jbabey	View Answer on Stackoverflow
Solution 2 - Javascript	usoban	View Answer on Stackoverflow
Solution 3 - Javascript	MMiroslav	View Answer on Stackoverflow
Solution 4 - Javascript	Rob I	View Answer on Stackoverflow

Escape dot in a regex range

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Socket.io Client: respond to all events with one handler?

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