基于empty函数的输出详解

$a = ‘‘;
echo ‘1.---------------‘.empty($a).‘<br>‘;
$a = ‘0‘;
echo ‘2.---------------‘.empty($a).‘<br>‘;
$a = 0;
echo ‘3.---------------‘.empty($a).‘<br>‘;
$a = null;
echo ‘4.---------------‘.empty($a).‘<br>‘;
$a = ‘null‘;
echo ‘5.---------------‘.empty($a).‘<br>‘;
$a = ‘abc‘;
echo ‘6.---------------‘.empty($a).‘<br>‘;
$a = true;
echo ‘7.---------------‘.empty($a).‘<br>‘;
$a = ‘true‘;
echo ‘8.---------------‘.empty($a).‘<br>‘;
$a = false;
echo ‘9.---------------‘.empty($a).‘<br>‘;
$a = ‘false‘;
echo ‘10.---------------‘.empty($a).‘<br>‘;
$a = 1;
echo ‘11.---------------‘.empty($a).‘<br>‘;
$a = ‘1‘;
echo ‘12.---------------‘.empty($a).‘<br>‘;
$a = ‘null‘;
echo ‘13.---------------‘.!empty($a).‘<br>‘;
结果：
1.---------------1
2.---------------1
3.---------------1
4.---------------1
5.---------------
6.---------------
7.---------------
8.---------------
9.---------------1
10.---------------
11.---------------
12.---------------
13.---------------1

基于empty函数的输出详解

原文：http://www.jb51.net/article/38603.htm