问一个Js的语法,在PHP该怎样表示?解决方法

问一个Js的语法,在PHP该怎样表示?
Javascript:

JScript code

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->
var a = 'a';
var b = null;
alert(a||b);
//这会输出a的变量值,,想问一下php应该怎么表示?

로그인 후 복사

PHP code

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->
$a = 'A';
$b = null;
echo $a || $b;
//这样只会输出1或0,,
//我以前记得在哪个Oauth的开发文档上看过...但我现在忘记了...
//不知道有能人能告诉一下本人..Thanks

로그인 후 복사