一. 字符串连接符

<?php
$x = 4;
echo "x minus one equals " . $x-1 . ", or so I hope";
?>

打印出来:

"-1, or so I hope"

二. and/or
嗯.php也有and/or这样的逻辑运算符.但是…

$bool = true && false;
var_dump($bool); // false, that's expected

$bool = true and false;
var_dump($bool); // true, ouch!
?>

原来’=’比’and/or’优先级高.