# `&#215;` #

- Unicode: `U+00D7 MULTIPLICATION SIGN`
- HTML: `&amp;times;`, `&amp;#215;`
- CSS: `\00d7`

See the Wikipedia article about the [multiplication sign](http://en.wikipedia.org/wiki/Multiplication_sign):

&gt; In mathematics, the symbol &#215; (read as times or multiplied by) is primarily used to denote the […]
&gt;
&gt; - Geometric dimension of an object, such as noting that a room is 10&#215;12 feet in area.

----

Depending on the context, the [`math` element](https://www.w3.org/TR/2016/REC-html51-20161101/semantics-embedded-content.html#mathml) (for [MathML](http://en.wikipedia.org/wiki/MathML)) element could be of use.

The proper question is which *character* should be used. The use of entity references for characters adds no semantics. There is no formal standard on denoting dimensions, but clearly this is about multiplication rather than the Latin letter x, so “x” (`&amp;times;`) is the correct character.

In practice, this is more of an orthography and typography question than about “semantic web”. Search engines, browsers, etc., don’t really care; it’s the human readers that matter.

You&#39;re doing everything correctly. I believe &#215; here is [semantically] related to the operation of multiplication, i.e. in fact you write the area by specifying two dimensions.

As part of a larger problem (adding a `,makeUniqueIDs` argument to `rbind.SpatialPolygonsDataFrame` for situations when the polygon IDs are identical), I&#39;m running into this weird message from rbind:

    &gt; do.call(&quot;rbind&quot;,xd.small)
    Error in match.names(clabs, names(xi)) : 
      names do not match previous names

 - [xd.small `dput` output](https://gist.github.com/3387091)

The only other info I could find on this was [this question](https://stackoverflow.com/questions/2504543/merge-multiple-data-frames-error-in-match-namesclabs-namesxi-names-do-n), which leads me to believe that `rbind` was at the root of the problem there also.

I can just write my own rbind-like function of course, but presumably this `match.names` check occurs for a reason, and I&#39;m curious what it is.

rbind error: &quot;names do not match previous names&quot;

I&#39;m Trying to get the current date plus 7 days to display. 

Example: Today is August 16, 2012, so this php snippet would output August 23, 2012.

       $date = strtotime($date);
       $date = strtotime(&quot;+7 day&quot;, $date);
       echo date(&#39;M d, Y&#39;, $date);

Right now, I&#39;m getting: Jan 08, 1970. What am I missing?

Return current date plus 7 days

Is the proper HTML entity for giving dimensions `&amp;times;`? I want to be semantically correct, but that begs the question, is listing a dimension as `2&quot; x 3&quot;` even semantic? If the *x* represents &quot;by&quot;, would I use the letter x or &amp;times;?

In my code I&#39;ve been using `2&amp;Prime;&amp;nbsp;&amp;times;&amp;nbsp;3&amp;Prime;`, or 2&amp;Prime;&amp;nbsp;&amp;times;&amp;nbsp;3&amp;Prime;. The non-breaking spaces are to prevent the dimension from being wrapped, as per the suggestions found in [The Elements of Typographic Style Applied to the Web][1].


  [1]: http://webtypography.net/Rhythm_and_Proportion/Etiquette_of_Hyphenation_and_Pagination/2.4.6/

What is the proper HTML entity for the &quot;x&quot; in a dimension?

Is the proper HTML entity for giving dimensions <code>&#x26;times;</code>? I want to be semantically correct, but that begs the question, is listing a dimension as <code>2" x 3"</code> even semantic? If the x represents "by", would I use the letter x or ×?
In my code I've been using <code>2&#x26;Prime;&#x26;nbsp;&#x26;times;&#x26;nbsp;3&#x26;Prime;</code>, or 2″ × 3″. The non-breaking spaces are to prevent the dimension from being wrapped, as per the suggestions found in <a href="http://webtypography.net/Rhythm_and_Proportion/Etiquette_of_Hyphenation_and_Pagination/2.4.6/" target="_blank" rel="noopener noreferrer">The Elements of Typographic Style Applied to the Web</a>.

What is the preferred method for setting CSS properties?

Inline style properties:

    &lt;div style=&quot;width:20px;height:20px;background-color:#ffcc00;&quot;&gt;&lt;/div&gt;

Style properties in `&lt;style&gt;...&lt;/style&gt;` tags:

    &lt;style&gt;.gold{width:20px;height:20px;background-color:#ffcc00;}&lt;/style&gt;&lt;div class=&quot;gold&quot;&gt;&lt;/div&gt;

Inline &lt;style&gt; tags vs. inline css properties

I&#39;m trying to create a regular expression to validate usernames against these criteria:

 1. Only contains *alphanumeric* characters,
    *underscore* and *dot*.
 2. Underscore and dot can&#39;t be at the *end* or
    *start* of a username (e.g `_username` / `username_` / `.username` / `username.`).
 3. Underscore and dot can&#39;t be *next to each other* (e.g `user_.name`).
 4. Underscore or dot can&#39;t be used multiple times *in a row* (e.g `user__name` / `user..name`).
 5. Number of characters must be between 8 to 20.

This is what I&#39;ve done so far; it sounds it enforces all criteria rules *but the 5th rule*. I don&#39;t know how to add the 5th rule to this:

     ^[a-zA-Z0-9]+([._]?[a-zA-Z0-9]+)*$

Regular expression to validate username

So, I have some PHP code that looks a bit like this:

    &lt;body&gt;
        The ID is 

        &lt;?php
        echo $_GET[&quot;id&quot;] . &quot;!&quot;;
        ?&gt;

    &lt;/body&gt;

Now, when I pass an ID like `http://localhost/myphp.php?id=26` it works alright, but if there is no ID like just `http://localhost/myphp.php` then it outputs:

    The ID is
    Notice: Undefined index: id in C:\xampp\htdocs\myphp.php on line 9
    !

I have searched for a way to fix this but I cannot find any way to check if a URL variable exists. I know there must be a way though.

How to verify if $_GET exists?

In the traditional way to add event listener:

    function getComboA(sel) {
        var value = sel.options[sel.selectedIndex].value;  
    }
    
    &lt;select id=&quot;comboA&quot; onchange=&quot;getComboA(this)&quot;&gt;
    &lt;option value=&quot;&quot;&gt;Select combo&lt;/option&gt;
    &lt;option value=&quot;Value1&quot;&gt;Text1&lt;/option&gt;
    &lt;option value=&quot;Value2&quot;&gt;Text2&lt;/option&gt;
    &lt;option value=&quot;Value3&quot;&gt;Text3&lt;/option&gt;
    &lt;/select&gt;

But I wanted to adapt to the `addEventListener` way:


    productLineSelect.addEventListener(&#39;change&#39;,getSelection(this),false);

    function getSelection(sel){
        var value = sel.options[sel.selectedIndex].value;
        alert(value);
    }

It doesn&#39;t work because I can&#39;t pass any parameter in `getSelection()` as the second parameter in `addEventListener` method? As far as I know I can only use the function name without parenthesises.

Any idea?

BTW, please look at [my previous question][1] about `console.log` doesn&#39;t work in Safari 6.0 Developer Inspector, I can&#39;t write any output in the console, which is frustrating.


  [1]: https://stackoverflow.com/q/12015540/456218

How to pass parameter to function using in addEventListener?

I know that the automatic rotation of JPG files is disabled in browsers.

They can not enable it because it would break the layout of some websites.

Is there a CSS property?
or javascript code to achieve that?
or something else?
or maybe the solution to this problem doesn&#39;t exist yet?

Is there a way to tell browsers to honor the jpeg exif orientation?

The newline character is represented by `&quot;\n&quot;` in C code. Is there an equivalent for the end-of-file (EOF) character?

Representing EOF in C code?

How can I get the number of characters of a string in Go?

For example, if I have a string `&quot;hello&quot;` the method should return `5`. I saw that `len(str)` returns the number of bytes **and not** the number of characters so `len(&quot;&#163;&quot;)` returns 2 instead of 1 because &#163; is encoded with two bytes in UTF-8.

How to get the number of characters in a string

How to get an &quot;E&quot; output rather than 69?

    package main

    import &quot;fmt&quot;

    func main() {
	    fmt.Print(&quot;HELLO&quot;[1])
    }

Does Golang have function to convert a char to byte and vice versa?

How to index characters in a Golang string?

How can I use modulo operator (%) in calculation of numbers for JavaScript projects?

How can I use modulo operator (%) in JavaScript?

Are there any **invisible** characters? I have checked Google for invisible characters and ended up with many answers but I&#39;m not sure about those. Can someone on Stack Overflow tell me more about this?

Also I have checked a profile on Facebook and found that the user didn&#39;t have any name to his profile? How can this be possible? Is it some database issue? Hacking or something?

When I searched over Internet, I found that `200D` is an ASCII value with an **invisible** character. Is it true? 


Invisible characters - ASCII

Unicode has a million icon-like glyphs, but they&#39;re very hard to search.

Is there a Unicode glyph that looks like a &quot;Binocular&quot; or &quot;magnifying glass&quot;?
Or is there a symbol that&#39;s used to mean &quot;Search&quot;, which is in Unicode?

Is there Unicode glyph Symbol to represent &quot;Search&quot;

I&#39;d like to use non breaking spaces in my JSF page. I know, in plain HTML I could use `&amp;nbsp;` for this and this works fine. However, when I put those `&amp;nbsp;` in a Facelets page, then it errors as follows:

&gt; Error Parsing /page.xhtml: Error Traced[line: 42] The entity &quot;nbsp&quot; was referenced, but not declared.

How is this caused and how can I solve it?

Error Parsing /page.xhtml: Error Traced[line: 42] The entity &quot;nbsp&quot; was referenced, but not declared

Since php 5.4 **html_entity_decode** introduces four new flags, with a minimal explanation

    ENT_HTML401	Handle code as HTML 4.01.
    ENT_XML1	Handle code as XML 1.
    ENT_XHTML	Handle code as XHTML.
    ENT_HTML5	Handle code as HTML 5. 


I want to understand what are they for. In which cases are they significant?    

My guess, (but may I be wrong) is that any different standard, encodes some unusual chars but any other don&#39;t, so in order to respect that, they are here.

My research: **htmlentities** has the same minimal explanation, with no examples too.  I have googled with no luck.

What do the ENT_HTML5, ENT_HTML401, ... modifiers on html_entity_decode do?

I want an optional line-breaking character that is always invisible that works with the `word-wrap: break-word;` CSS style.

Here are some specifics. My goal is to break apart long links in reasonable places. These characters are a good place to start: `-`, `.`, `_`, `/`, `\`. This is not a Rails-specific question, but I wanted to share some code I&#39;m using now:

    module ApplicationHelper
      def with_optional_line_breaks(text)
        text.gsub(%r{([-._/\\])}, &#39;\1&amp;shy;&#39;)
      end
    end

Here&#39;s the problem with the code above: when `&amp;shy;` takes effect (in a table with: `word-wrap: break-word;`), `&amp;shy;` gets displayed as `-`. I don&#39;t want to see the `-`; I want a line break without any character shown.




----------

Optional line-breaking HTML entity that is always invisible

I am pulling a JSON file from a site and one of the strings received is:

&lt;!-- language: none --&gt;

    The Weeknd &amp;#8216;King Of The Fall&amp;#8217; [Video Premiere] | @TheWeeknd | #SoPhi

How can I convert things like `&amp;#8216` into the correct characters?

I&#39;ve made a Xcode Playground to demonstrate it:

    import UIKit

    var error: NSError?
    let blogUrl: NSURL = NSURL.URLWithString(&quot;http://sophisticatedignorance.net/api/get_recent_summary/&quot;)
    let jsonData = NSData(contentsOfURL: blogUrl)

    let dataDictionary = NSJSONSerialization.JSONObjectWithData(jsonData, options: nil, error: &amp;error) as NSDictionary

    var a = dataDictionary[&quot;posts&quot;] as NSArray

    println(a[0][&quot;title&quot;])




How do I decode HTML entities in Swift?

Do all of the following carry the same semantic meaning?
If not please explain your answer.

&lt;br&gt;**1.**

    &lt;nav&gt;
        &lt;ul&gt;
            &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
            &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
            &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
            &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
        &lt;/ul&gt;
    &lt;/nav&gt;

&lt;br&gt;**2.**

    &lt;div role=&quot;navigation&quot;&gt;
        &lt;ul&gt;
            &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
            &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
            &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
            &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
        &lt;/ul&gt;
    &lt;/div&gt;

&lt;br&gt;**3.**

    &lt;ul role=&quot;navigation&quot;&gt; 
    &lt;! -- breaks HTML5 specification 3.2.7.4 Implicit ARIA Semantics
          navigation is not an allowed value of role on ul --&gt;
        &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
        &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
        &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
        &lt;li&gt;&lt;a href=&quot;#&quot;&gt;link&lt;/li&gt;
    &lt;/ul&gt;

HTML5 nav element vs. role=&quot;navigation&quot;

I am a UX architect working with a team of Android developers that are mostly junior. We are having issues properly setting line height in Android. 

We are using the Material Design spec as our guide for our app. In particular, you can see line height specs here:

https://material.google.com/style/typography.html#typography-line-height

Let&#39;s use Body 2 as our example. The spec says the type is 13sp or 14sp, and the leading (line height - same thing) should be 24dp. 

Here&#39;s the problem: these devs are telling me there is no such way to set line height like that in the code. Instead, they are telling me to measure the distance between the two lines of text and give them that measure - let&#39;s say it&#39;s 4dp. They want this for each style of text we are using. 

We are using a Sketch &gt; Zepelin flow for spec. 

It seems odd to me to be able to create a font style (which could easily be class/style in the code) that is 13sp with 24dp leading, and not be able to set the leading, but instead have to add a 3rd measure to the mix. There is no place in Sketch or Zepelin for such a measure &quot;between lines.&quot;

Is this really the way it is done, or is there a proper way to set line height? 

Content Type	Original Author	Original Content on Stackoverflow
Question	Nick	View Question on Stackoverflow
Solution 1 - Html	unor	View Answer on Stackoverflow
Solution 2 - Html	Jukka K. Korpela	View Answer on Stackoverflow
Solution 3 - Html	Kryzhovnik	View Answer on Stackoverflow

What is the proper HTML entity for the "x" in a dimension?

Html Problem Overview

Html Solutions

Solution 1 - Html

`×`

Solution 2 - Html

Solution 3 - Html

Return current date plus 7 days

rbind error: "names do not match previous names"

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