How to count number of parameters passed in PHP function

Before starting this article, I don’t know how much you know about PHP functions. If you are still a newbie, I recommend that you read the "PHP Function" chapter in the PHP self-study manual. After all, There is a saying that the real power of PHP comes from its functions~

So this article will introduce you to the basic knowledge about functions: calculating the number of parameters passed in the PHP function.

First of all, I will briefly introduce how to create a function:

is as follows:

<?php
function functionName($x,$y)
{
    // 要执行的代码
}

In PHP, you can create a function through the function keyword. "functionName" represents the custom function name; ($x,$y) represents the passed parameters. Two parameters $x and $y are clearly defined here; {...} is the function code to be executed. .

After briefly introducing the creation of functions, we will go straight to the topic!

How to count the number of parameters passed in a PHP function?

The answer is: In PHP, you can use the func_num_args() function to count the number of parameters passed into the PHP function.

The sample code is as follows:

<?php
function count_param()
{
    $count_args = func_num_args();
    echo "参数的数量: $count_args\n";
}

count_param(10, 20);  // 参数个数: 2

Output:

参数的数量: 2

In the above code, it can be clearly seen that the parameters we pass to the function are (10, 20) That is, 2 parameters, and the result of calculating the number of parameters is also 2.

Here you need to understand the func_num_args() function. The introduction to the func_num_args() function is as follows:

func_num_args()The function is used to return the number of parameters passed to the function. Its syntax is "func_num_args(): int";

The return value is: Returns the number of parameters passed into the current user-defined function .

This function can be used with func_get_arg() and func_get_args() to allow user-defined functions to accept variable-length argument lists.

Note: If called from outside a user-defined function, a warning is generated.

Finally, I would like to recommend the latest and most comprehensive "PHP Video Tutorial"~ Come and learn!

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