PHP:获取函数需要的参数数 [英] PHP: Get number of parameters a function requires
问题描述
我相信这是我正在寻找,但它在python not php:编程确定参数一个函数需要的数量 - Python
And I believe this is what I'm looking for but it's in python not php: Programatically determining amount of parameters a function requires - Python
假设我有这样的函数:
function client_func($cls, $arg){ }
当我准备调用这个函数时,我可能在伪代码中做这样的事情:
and when I'm ready to call this function I might do something like this in pseudo code:
if function's first parameter equals '$cls', then call client_func(instanceof class, $arg)
else call client_func($arg)
基本上,有一种方法来预测函数并查看需要什么参数值在调用函数之前。
So basically, is there a way to lookahead to a function and see what parameter values are required before calling the function.
我想这将像debug_backtrace,但是反过来。
I guess this would be like debug_backtrace, but the other way around.
func_get_args
func_get_args() can only be called from within a function which doesn't help me here.
任何想法?
推荐答案
使用反射,特别是 ReflectionFunction 。
$fct = new ReflectionFunction('client_func');
echo $fct->getNumberOfRequiredParameters();
据我所见,你会发现 getParameters()也很有用
As far as I can see you will find getParameters() useful too
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