    $description = &#39;Paper: &#39; . ($paperType == &#39;bond&#39; ? &#39;Bond&#39; : &#39;Other&#39;);

Try adding parentheses so the string is concatenated to a string in the right order.

It is related with operator precedence. You have to do the following:

    $description = &#39;Paper: &#39; . (($paperType == &#39;bond&#39;) ? &#39;Bond&#39; : &#39;Other&#39;);


I think everyone gave the solution, I would like to contribute the reason for the unexpected result.

First of all here you can check the origin, and how the operators are evaluated (left, right, associative, etc).

http://php.net/manual/fa/language.operators.precedence.php

Now if we analyze your sentence.

    $ paperType = &#39;bond&#39;;
    $ description = &#39;Paper:&#39;. ($ paperType == &#39;bond&#39;)? &#39;Bond&#39;: &#39;Other&#39;;

1) We review the table and find that the parentheses are evaluated first, then the &#39;.&#39; (concatenation) is evaluated and at the end the ternary operator &#39;?&#39;, therefore we could associate this as follows:


    // evaluate the parenthesis ... ($ paperType == &#39;bond&#39;)
    $ description = (&#39;Paper:&#39;. 1)? &#39;Bond&#39;: &#39;Other&#39;;
    //result
    $ description = &#39;Paper: 1&#39;? &#39;Bond&#39;: &#39;Other&#39;;

2) We now have the ternary operator, we know that a string is evaluated &quot;true&quot;

// php documentation
When converting to boolean, the following values ​​are considered FALSE:

...
the empty string, and the string &quot;0&quot;

    $ description = true? &#39;Bond&#39;: &#39;Other&#39;;

3) Finally

    $ description = &#39;bond&#39;;


I hope I have clarified the question.
Greetings.

I&#39;ve had an asp.net website running live on our intranet for a couple of weeks now. I just got an email from my application_error emailer method with an unhandled exception. 

Here it is (I&#39;ve cleaned up some of the paths to make it better displayed)

&gt; Exception : Object reference not set to an instance of an object.
Stack Trace : at System.Collections.Generic.Dictionary\`2.Insert(TKey key, TValue value, Boolean add) at System.Collections.Generic.Dictionary\`2.Add(TKey key, TValue value)
 at TimesheetDomain.DataMappers.StaffMemberData.ReadStaff(SqlDataReader reader) in TimesheetDomain\DataMappers\StaffMemberData.cs:line 362
&gt; 
&gt;  at
&gt; TimesheetDomain.DataMappers.StaffMemberData.GetStaffMember(String
&gt; name) in
&gt; TimesheetDomain\DataMappers\StaffMemberData.cs:line
&gt; 401
&gt; 
&gt;  at
&gt; TimesheetDomain.ServiceLayer.TimesheetManager.GetUserFromName(String
&gt; name) in
&gt; TimesheetDomain\ServiceLayer\TimesheetManager.cs:line
&gt; 199 
&gt; 
&gt; at UserVerification.GetCurrentUser()
&gt; in \App_Code\UserVerification.cs:line
&gt; 29 at WebTimesheets.OnInit(EventArgs
&gt; e) in
&gt; \WebTimesheets\WebTimesheets.master.cs:line
&gt; 159
&gt; 
&gt;  at
&gt; System.Web.UI.Control.InitRecursive(Control
&gt; namingContainer) at
&gt; System.Web.UI.Control.InitRecursive(Control
&gt; namingContainer) at
&gt; System.Web.UI.Page.ProcessRequestMain(Boolean
&gt; includeStagesBeforeAsyncPoint, Boolean
&gt; includeStagesAfterAsyncPoint)


Basically it looks like it&#39;s erroring at my ReadStaff method which reads a data reader to build staff member objects. Here is the bit of code:

    while (reader != null &amp;&amp; reader.Read())
    {
        StaffMember newMember = null;
        string firstName = reader[&quot;FirstName&quot;].ToString();
        string lastName = reader[&quot;LastName&quot;].ToString();
        int staffID = (int)reader[&quot;StaffID&quot;];
        int employSection = (int)reader[&quot;EmploySection&quot;];
        StaffType employType = (StaffType)employSection;
        string emailAddress = reader[&quot;EmailInt&quot;].ToString();
        int employCode = (int)reader[&quot;ibbwid&quot;];

        //check if they are an admin staff member 
        if (IsAdminStaff(employType))
        {
            newMember = new AdminOfficer(firstName, lastName, employType, staffID, emailAddress, employCode);
        }
        else
        {
            //check if they are a supervisor
            if (IsASupervisor(staffID))
                newMember = new Supervisor(firstName, lastName, employType, staffID, emailAddress, employCode);
            else
                newMember = new StaffMember(firstName, lastName, employType, staffID, emailAddress, employCode);
        }

        //add to identity map
        if (!_staffMembers.ContainsKey(staffID))
            _staffMembers.Add(staffID, newMember); //****THIS IS LINE 362*****
        else
            _staffMembers[staffID] = newMember;
    }

(Line 362 is 3rd last line)
I&#39;m using an identity map (just read fowlers book on patterns and thought it was a good idea - may have done it wrong, happy for comments) but that&#39;s not overly relevant as later on I use the `newMember` object elsewhere so if I remove that block the `NullReferenceException` will occur.

I am struggling to see how on earth `newMember` is null in the 3rd last line there (which is the line that errored). 

Resharper/VS doesn&#39;t give me a warning that it could be `null` - because there&#39;s the 3 constructors which I choose from. 

Can anyone suggest where I can look to try and fix this error? It&#39;s only happened once and that method has been called thousands of times since the site went live. 

Thanks

[EDIT]
As Requested, here&#39;s the IComparer for staff member

    /// &lt;summary&gt;
    /// Comparer for staff members - compares on name
    /// &lt;/summary&gt;
    public class StaffMemberComparer : IComparer
    {
        public int Compare(object x, object y)
        {
            //check they are staff members
            if (x is StaffMember &amp;&amp; y is StaffMember)
            {
                //do a simple string comparison on names
                StaffMember staffX = x as StaffMember;
                StaffMember staffY = y as StaffMember;

                return String.Compare(staffX.FirstName, staffY.FirstName);
            }

            throw new Exception(&quot;This is for comparing Staff Members&quot;);
        }
    }

and it&#39;s used in the IComparable implementation

    /// &lt;summary&gt;
    /// IComparable implementaiton
    /// &lt;/summary&gt;
    /// &lt;param name=&quot;obj&quot;&gt;object to compare to&lt;/param&gt;
    /// &lt;returns&gt;&lt;/returns&gt;
    public int CompareTo(object obj)
    {
        StaffMemberComparer comparer = new StaffMemberComparer();
        return comparer.Compare(this, obj);
    }



How did I get this NullReferenceException error here right after the constructor?

I am using xmllint --schema option to validate my XML that looks like this

    &lt;XML&gt;
    &lt;Active&gt;True&lt;/Active&gt;
    &lt;/XML&gt;

In my schema file, I have following line that describes Active element.

    &lt;xsd:element name=&quot;Active&quot; type=&quot;xs:boolean&quot; /&gt;

When I run xmllint, I get error messages that says 

&gt; /tmp/schema_validation.xml:73: element
&gt; Active: Schemas validity error :
&gt; Element &#39;Active&#39;: &#39;True&#39; is not a
&gt; valid value of the atomic type
&gt; &#39;xs:boolean&#39;.

When I change the XML to

    &lt;Active&gt;true&lt;/Active&gt;

Then the error message disappears.

So, it looks like xsd:boolean means it&#39;s all lowercase &quot;true/false&quot; but not &quot;True/False&quot; to xmllint.. My question is, how can I make xmllint to accept &quot;True&quot; for xsd:boolean type? Or is there different tools that I can use that will validate this XML? Changing the XML or schema is not my option at this point.

Thanks!

xsd:boolean element type accept &quot;true&quot; but not &quot;True&quot;. How can I make it accept it?

Hi I just want to know why this code yields (at least for me) an incorrect result.

Well, probably i&#39;m in fault here

    $description = &#39;Paper: &#39; . ($paperType == &#39;bond&#39;) ? &#39;Bond&#39; : &#39;Other&#39;;

I was guessing that if paperType equals &#39;Bond&#39; then description is &#39;Paper: Bond&#39; and  if paperType is not equals to &#39;Bond&#39; then description is &#39;Paper: Other&#39;.

But when I run this code the results are description is either &#39;Bond&#39; or &#39;Other&#39; and left me
wondering where the string &#39;Paper: &#39; went???



Ternary operator and string concatenation quirk?

Hi I just want to know why this code yields (at least for me) an incorrect result.
Well, probably i'm in fault here
<pre><code class="hljs language-ini">$description = 'Paper: ' . ($paperType == 'bond') ? 'Bond' : 'Other';
</code></pre>
I was guessing that if paperType equals 'Bond' then description is 'Paper: Bond' and if paperType is not equals to 'Bond' then description is 'Paper: Other'.
But when I run this code the results are description is either 'Bond' or 'Other' and left me
wondering where the string 'Paper: ' went???

Is it possible, in PHP, to flatten a (bi/multi)dimensional array without using recursion or references?

I&#39;m only interested in the values so the keys can be ignored, I&#39;m thinking in the lines of `array_map()` and `array_values()`.

How to Flatten a Multidimensional Array?

I have a PHP array with numbers of ID&#39;s in it. These numbers are already ordered.

Now i would like to get my result via the IN() method, to get all of the ID&#39;s.

However, these ID&#39;s should be ordered like in the IN method.

For example:

    IN(4,7,3,8,9)  
Should give a result like:

    4 - Article 4  
    7 - Article 7  
    3 - Article 3  
    8 - Article 8  
    9 - Article 9

Any suggestions?  Maybe there is a function to do this?

Thanks!

MySQL ORDER BY IN()

In my block code I am trying to programmatically retrieve a list of products that have a attribute with a specific value.

Alternately if that is not possible how would one retrieve all products then filter them to just list the products with a specific attribute?

How would I perform a search using standard boolean filters `AND` or `OR` to match a subset of my products?

Magento - Retrieve products with a specific attribute value

Directory is something like:

    home/
        file1.html
        file2.html
    Another_Dir/
        file8.html
        Sub_Dir/
            file19.html

I am using the same PHP Zip class used in PHPMyAdmin [http://trac.seagullproject.org/browser/branches/0.6-bugfix/lib/other/Zip.php][1] . I&#39;m not sure how to zip a directory rather than just a file. Here&#39;s what I have so far:


    $aFiles = $this-&gt;da-&gt;getDirTree($target);
    /* $aFiles is something like, path =&gt; filetime
    Array
    (
        [home] =&gt; 
        [home/file1.html] =&gt; 1251280379
        [home/file2.html] =&gt; 1251280377
        etc...
    )
    
    */
    $zip = &amp; new Zip();
    foreach( $aFiles as $fileLocation =&gt; $time ){
        $file = $target . &quot;/&quot; . $fileLocation;
        if ( is_file($file) ){
            $buffer = file_get_contents($file);
            $zip-&gt;addFile($buffer, $fileLocation);
        }
    }
    THEN_SOME_PHP_CLASS::toDownloadData($zip); // this bit works ok


but when I try to unzip the corresponding downloaded zip file I get &quot;operation not permitted&quot;

This error only happens when I try to unzip on my mac, when I unzip through the command line the file unzips ok. Do I need to send a specific content type on download, currently &#39;application/zip&#39;

  [1]: http://trac.seagullproject.org/browser/branches/0.6-bugfix/lib/other/Zip.php

How to [recursively] Zip a directory in PHP?

At work we have to use a proxy to basically access port 80 for example, we have our own custom logins for each user.

My temporary workaround is using curl to basically login as myself through a proxy and access the external data I need.

Is there some sort of advanced php setting I can set so that internally whenever it tries to invoke something like `file_get_contents()` it always goes through a proxy? I&#39;m on Windows ATM so it&#39;d be a pain to recompile if that&#39;s the only way.

The reason my workaround is temporary is because I need a solution that&#39;s generic and works for multiple users instead of using one user&#39;s credentials ( Ive considered requesting a separate user account solely to do this but passwords change often and this technique needs to be deployed throughout a dozen or more sites ). I don&#39;t want to hard-code credentials basically to use the curl workaround.

file_get_contents behind a proxy?

&gt; **Possible Duplicate:**
&gt; [What are the PHP operators “?” and “:” called and what do they do?](https://stackoverflow.com/questions/1080247)

&lt;!-- End of automatically inserted text --&gt;

From http://twitto.org/

    &lt;?PHP
        require __DIR__.&#39;/c.php&#39;;
        if (!is_callable($c = @$_GET[&#39;c&#39;] ?: function() { echo &#39;Woah!&#39;; }))
            throw new Exception(&#39;Error&#39;);
        $c();
    ?&gt;

Twitto uses several new features available as of PHP 5.3:

 1. The __DIR__ constant
 2. The ?: operator
 3. Anonymous functions

----------

 1. What does number 2 do with the **?:** in PHP 5.3?

 2. Also, what do they mean by anonymous functions? Wasn&#39;t that something that has existed for a while?



What is ?: in PHP 5.3?

I&#39;m just getting into Python and I really like the terseness of the syntax. However, is there an easier way of writing an `if`-`then`-`else` statement so it fits on one line?

For example:

    if count == N:
        count = 0
    else:
        count = N + 1

Is there a simpler way of writing this? I mean, in Objective-C I would write this as:

    count = count == N ? 0 : count + 1;

Is there something similar for Python?

**Update**

I know that in this instance I can use `count == (count + 1) % N`. 

I&#39;m asking about the general syntax.


Putting a simple if-then-else statement on one line

I was wondering if there was a ternary operator (condition ? true-value : false-value) that could be used in a Django template.  I see there is a python one (true-value if condition else false-value) but I&#39;m unsure how to use that inside a Django template to display the html given by one of the values.  Any ideas?

Django Template Ternary Operator

How is the conditional operator (`? :`) used in Ruby?

For example, is this correct?

    &lt;% question = question.size &gt; 20 ? question.question.slice(0, 20)+&quot;...&quot; : question.question %&gt;

How do I use the conditional operator (? :) in Ruby?

    public string Source
    {
    	get
    	{
    		/*
    		if ( Source == null ){
    			return string . Empty;
    		} else {
    			return Source;
    		}
    		*/
    		return Source ?? string.Empty;
    	}
    	set
    	{
    		/*
    		if ( Source == null ) {
    			Source = string . Empty;
    		} else {
    			if ( Source == value ) {
    				Source = Source;
    			} else {
    				Source = value;
    			}
    		}
    		*/
    		Source == value ? Source : value ?? string.Empty;
    		RaisePropertyChanged ( &quot;Source&quot; );
    	}
    }


Can I use `?:` `??` operators **EXACTLY** as If/Else?
  


----------
  
**My Question :**  
How to write the following with ?: ?? operators  

**[ 1 ]**

    if ( Source == null ){
	    // Return Nothing
	} else {
		return Source;
	}

  
**[ 2 ]**


    if ( Source == value ){
		// Do Nothing
	} else {
		Source = value;
		RaisePropertyChanged ( &quot;Source&quot; );
	} 

**Briefly** : How to do nothing, return nothing and do multiple instructions with `?:` `??` operator?

?: ?? Operators Instead Of IF|ELSE

I have to concatenate these two strings from my resource/value files:

    &lt;string name=&quot;Toast_Memory_GameWon_part1&quot;&gt;you found ALL PAIRS ! on &lt;/string&gt;
    &lt;string name=&quot;Toast_Memory_GameWon_part2&quot;&gt; flips !&lt;/string&gt;

I do it this way :

    String message_all_pairs_found = getString(R.string.Toast_Memory_GameWon_part1)+total_flips+getString(R.string.Toast_Memory_GameWon_part2);
    
    Toast.makeText(this, message_all_pairs_found, 1000).show();

But the spaces at the end of the first string and at the beginning of the second string
have disappeared (when the Toast is shown) ...

What should I do ?

I guess the answer is somewhere here in this [documentation link][1]


or is it something like using **`&amp;amp ;`** for the &quot;&amp;&quot; character ??


  [1]: http://developer.android.com/reference/java/util/regex/package-descr.html#impnotes

How to keep the spaces at the end and/or at the beginning of a String?

In Go, a `string` is a primitive type, which means it is read-only, and every manipulation of it will create a new string. 

So if I want to concatenate strings many times without knowing the length of the resulting string, what&#39;s the best way to do it?

The naive way would be:

    var s string
    for i := 0; i &lt; 1000; i++ {
        s += getShortStringFromSomewhere()
    }
    return s

but that does not seem very efficient.

How to efficiently concatenate strings in go

I need to concatenate two const chars like these:

    const char *one = &quot;Hello &quot;;
    const char *two = &quot;World&quot;;

How might I go about doing that?

I am passed these `char*`s from a third-party library with a C interface so I can&#39;t simply use `std::string` instead.

const char* concatenation

I have a directory for which I want to list all the `.doc` files with a `;`.

I know the following batch command echos all the files:
    
    for /r %%i In (*.doc) DO echo %%i

But now I want to put them all in a variable, add a `;` in between and echo them all at once.  
How can I do that?

    set myvar=&quot;the list: &quot;
    for /r %%i In (*.doc) DO &lt;what?&gt;
    echo %myvar%

How to concatenate strings in a Windows batch file?

I want append to a string so that every time I loop over it, it will add &quot;test&quot; to the string.


Like in `PHP` you would do:
    
    $teststr = &quot;test1\n&quot;
    $teststr .= &quot;test2\n&quot;
    echo = &quot;$teststr&quot;
Returns:
 
    test1
    test2
    
But I need to do this in a shell script

Content Type	Original Author	Original Content on Stackoverflow
Question	Cesar	View Question on Stackoverflow
Solution 1 - Php	meder omuraliev	View Answer on Stackoverflow
Solution 2 - Php	João Silva	View Answer on Stackoverflow
Solution 3 - Php	hizmarck	View Answer on Stackoverflow

Ternary operator and string concatenation quirk?

Php Problem Overview

Php Solutions

Solution 1 - Php

Solution 2 - Php

Solution 3 - Php

xsd:boolean element type accept "true" but not "True". How can I make it accept it?

How did I get this NullReferenceException error here right after the constructor?

Attributions