In PHP
string data is enclosed in quotes either single or double quotes. But sometimes
programmers get confused in difference between single quote and double quote.
Let me tell you what is main difference
between single quotes and double quotes theoretically & also practically too.
Single quotes do not support
variable expansion but double quotessupport.Means if there is a string with
single quotes and if you place a variable in that, it won’t substitute its
value in string.
e.g.
<?PHP
$str = 'QAPHP';
echo '$str is a Blog which provides
Question & Answers.';
?>
Output
will be:: $str is a site which provides Question & Answers.
In
case of double quoted string…
<?PHP
$str = 'QAPHP';
echo "$str is a site which
provides tips.";
?>
Output
will be:: QAPHP is a Blog which provides Question & Answers.
Means if there is a string with double quotes and if you
place a variable in that, it will substitute its value in string.
This is the main difference.
Reference : http://www.scriptvenue.com/2011/10/difference-between-double-quotes-and-single-quotes-in-php/
