Note 011 Implementation of PHP variable parameter function

I often use the variable parameter function in Js and find it very convenient to use. Suddenly it occurred to me whether related functions can also be implemented in PHP?

I asked Du Niang, and Du Niang told me that this idea is feasible. That is to say, during the search process, the two functions func_get_arg and func_get_args came into my eyes. I have come across these two functions before, and I roughly know that there is such a thing. However, because there was no need or consideration in this area at the time, I did not have an in-depth understanding of the usage of the two functions.

func_get_arg The function of this function is to obtain the parameter value specified in a function. The syntax format is: func_get_arg(arg_num), where arg_num refers to the numerical index of the parameter. In the world of programming, the first number is not 1, but 0. I believe this goes without saying.

func_get_args The function of this function is to obtain all parameter values ​​​​in a function and return them in the form of an array. This function requires no parameters to be passed. This function is the key to realizing the variable parameter function.

By using the func_get_args function in a function to obtain all parameters of the function, and then perform certain logical processing on these parameters, that is, perform different logical operations based on different parameters, this is achieved. We need the variadic function.

There is also a function: func_num_args. The function of this function is to return the number of parameters in the function. Using this function in combination with the previously mentioned functions can more easily achieve the functions we need.

The specific example of Hy369 is not provided in the blog (in fact, this is making excuses for my laziness). If you understand the principle, there should be no problem in implementing the variable parameter function. After all, we are all legends. Siege Lion is not, haha.

The above is the content of note 011 on the implementation of PHP variable parameter function. For more related content, please pay attention to the PHP Chinese website (www.php.cn)!