Paste_Image.png
Paste_Image.png
$functionName='md5';
echo $functionName('king');//md5()
//b2086154f101464aab3328ba7e060deb
get_defined_functions
//get_defined_functions()
//得到所有已定义的函数，返回数组，包含系统函数和用户自定义的函数
var_dump(get_defined_functions());
array
'internal' =>
array
0 => string 'zend_version' (length=12)
1 => string 'func_num_args' (length=13)
2 => string 'func_get_arg' (length=12)
3 => string 'func_get_args' (length=13)
4 => string 'strlen' (length=6)
5 => string 'strcmp' (length=6)
6 => string 'strncmp' (length=7)
7 => string 'strcasecmp' (length=10)
8 => string 'strncasecmp' (length=11)
...
...
'user' =>
array
empty
