Home >Backend Development >PHP Tutorial >解析PHP中empty is_null和isset的测试_PHP
解析PHP中empty is_null和isset的测试_PHP
- WBOYOriginal
- 2016-06-01 12:05:121005browse
代码如下:
复制代码 代码如下:
$a;
$b = false;
$c = '';
$d = 0;
$e = null;
$f = array();
首先是empty的var_dump输出:
boolean true
boolean true
boolean true
boolean true
boolean true
boolean true
然后是is_null的输出:
boolean true
boolean false
boolean false
boolean false
boolean true
boolean false
最后是isset的输出:
boolean false
boolean true
boolean true
boolean true
boolean false
boolean true
由此可见 empty() 可以用来判定所有的数据类型是否为空或假,而 is_null 与 isset 基本一样,只能用来判断是否为NULL和未定义.
Statement：
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Previous article：浅析Dos下运行php.exe,出现没有找到php_mbstring.dll 错误的解决_PHPNext article：解析PHP中VC6 X86和VC9 X86的区别及 Non Thread Safe的意思_PHP