<tt>6 is my lucky number</tt>
 
<tt>6 is my lucky number</tt>
   −
We can also performa calculation and have the result included in the concatenation:
+
We can also perform a calculation and have the result included in the concatenation:
    
<pre>
 
<pre>
 
<tt>11 is my lucky number</tt>
 
<tt>11 is my lucky number</tt>
   −
it is important to note an issue when dealing with strings and numbers. While the above works fine because we began the expression with the addition something different happens when we have the addition afer the string:
+
It is important to note an issue when dealing with strings and numbers. While the above works fine because we began the expression with the addition, something very different happens when we have the addition afer the string:
    
<pre>
 
<pre>
 
</pre>
 
</pre>
   Exception encountered, of type "Error"
[db85ca3e] /index.php?title=PHP_Operators&diff=1169&oldid=1168 Error from line 434 of /var/www/techotopia/includes/diff/DairikiDiff.php: Call to undefined function each()
Backtrace:
#0 /var/www/techotopia/includes/diff/DairikiDiff.php(544): DiffEngine->diag()
#1 /var/www/techotopia/includes/diff/DairikiDiff.php(344): DiffEngine->compareSeq()
#2 /var/www/techotopia/includes/diff/DairikiDiff.php(227): DiffEngine->diffLocal()
#3 /var/www/techotopia/includes/diff/DairikiDiff.php(721): DiffEngine->diff()
#4 /var/www/techotopia/includes/diff/DairikiDiff.php(859): Diff->__construct()
#5 /var/www/techotopia/includes/diff/DairikiDiff.php(980): MappedDiff->__construct()
#6 /var/www/techotopia/includes/diff/TableDiffFormatter.php(194): WordLevelDiff->__construct()
#7 /var/www/techotopia/includes/diff/DiffFormatter.php(140): TableDiffFormatter->changed()
#8 /var/www/techotopia/includes/diff/DiffFormatter.php(82): DiffFormatter->block()
#9 /var/www/techotopia/includes/diff/DifferenceEngine.php(881): DiffFormatter->format()
#10 /var/www/techotopia/includes/diff/DifferenceEngine.php(797): DifferenceEngine->generateTextDiffBody()
#11 /var/www/techotopia/includes/diff/DifferenceEngine.php(728): DifferenceEngine->generateContentDiffBody()
#12 /var/www/techotopia/includes/diff/DifferenceEngine.php(662): DifferenceEngine->getDiffBody()
#13 /var/www/techotopia/includes/diff/DifferenceEngine.php(632): DifferenceEngine->getDiff()
#14 /var/www/techotopia/includes/diff/DifferenceEngine.php(453): DifferenceEngine->showDiff()
#15 /var/www/techotopia/includes/page/Article.php(797): DifferenceEngine->showDiffPage()
#16 /var/www/techotopia/includes/page/Article.php(508): Article->showDiffPage()
#17 /var/www/techotopia/includes/actions/ViewAction.php(44): Article->view()
#18 /var/www/techotopia/includes/MediaWiki.php(490): ViewAction->show()
#19 /var/www/techotopia/includes/MediaWiki.php(287): MediaWiki->performAction()
#20 /var/www/techotopia/includes/MediaWiki.php(714): MediaWiki->performRequest()
#21 /var/www/techotopia/includes/MediaWiki.php(508): MediaWiki->main()
#22 /var/www/techotopia/index.php(41): MediaWiki->run()
#23 {main}