Example usage of single quotes and double quotes in PHP_PHP tutorial

""Fields enclosed in double quotes will be interpreted by the compiler and then output as HTML code.

'' The words inside the single quotes are not interpreted and are output directly.

Both single quotes and double quotes have their own uses.

The content in single quotes will not be parsed, which is more efficient.

Such as the following code:

$url='http://www.bkjia.com';

//Single quote output

$output= '$ url';

echo 'Single quote output:'.$output.'
';

//Double quote output

$output=" $url";

echo "Double quote output:".$output;

?>

The output is as follows: