A problem with global and include in PHP

I am a novice. I don’t understand some things in my study and it is not easy to search, so I sent it here to ask everyone.
Thank you in advance for all the answers and help.

As in the title:

<code>目前有 a.php b.php c.php 三个文件
</code>

The pseudo code of a.php is as follows:

<code><?php
function say($key,$val){
    global $array;
    $array[$key]=$val;
    extract($array);
}
function write($name){
    include_once($name.".php");
}

$action = $_GET['a'];//假设当前 url: a.php?a=b
include_once($action.".php");
$action();</code>

b.php code is as follows

<code><?php
function b(){
    say("str","thinks");
    write("c");
}</code>

c.php

<code><?php
var_dump($str);</code>

---

The goal that needs to be achieved is that the variable value can be read directly in the C.PHP file.

---

The general logic is as above. In addition, I personally feel that this part is similar to assign/display in the framework, but I don’t know how to implement it.

The above code reports an error: Notice: Undefined variable: str

I hope you guys can give me some advice (or writing habits, etc.).
Thank you.

Reply content:

I am a novice. I don’t understand some things in my study and it is not easy to search, so I sent it here to ask everyone.
Thank you in advance for all the answers and help.

As in the title:

<code>目前有 a.php b.php c.php 三个文件
</code>

The pseudo code of a.php is as follows:

<code><?php
function say($key,$val){
    global $array;
    $array[$key]=$val;
    extract($array);
}
function write($name){
    include_once($name.".php");
}

$action = $_GET['a'];//假设当前 url: a.php?a=b
include_once($action.".php");
$action();</code>

b.php code is as follows

<code><?php
function b(){
    say("str","thinks");
    write("c");
}</code>

c.php

<code><?php
var_dump($str);</code>

---

The goal that needs to be achieved is that the variable value can be read directly in the C.PHP file.

---

The general logic is as above. In addition, I personally feel that this part is similar to assign/display in the framework, but I don’t know how to implement it.

The above code reports an error: Notice: Undefined variable: str

I hope you guys can give me some advice (or writing habits, etc.).
Thank you.

global $array; only modifies the scope of $array, but extract($array); is executed within the function, so the scope of $str is still inside the function. You can do this in c.php var_dump($arr['str']).

As for the two sentences you said, "In addition, I personally feel that this part is similar to assign/display in the framework" and "But I don't know how to implement it" are contradictory. You don't know how to implement it, so why do you Do you think this part is similar to assign/display in the framework?

It’s the same if you use class to write your example. You don’t need to define three files separately, and it looks comfortable. However, the function you use shows that you can’t think well in object-oriented thinking, and your steps are not stable. When we give Your sprint technique certainly doesn't make sense.

All variables in

PHP have scopes. The template engines you see using assign/display and other forms in the framework all put the extract output variables and the include imported template files in the same In the function, only in this way can the variable scope be consistent, and the value of the variable can be obtained from the imported file. As for your way of writing, splitting the two operations into different functions, of course they cannot access each other. Don't say you want to get the value of the variable in c.php, you can't get it directly after say("str", "thinks");.

It seems that you haven’t really understood the issue of global and internal variable scope of functions. It is recommended to check their concepts or usage again!
According to your idea, $str in var_dump($str); is the parameter 'str' in extract($array);. In fact, what you want var_dump to obtain at this time is the variable $str in the say function.
What you do is nothing more than:

<code>function a(){
    $str = '123';
}
a();
var_dump($str);</code>

You can’t get $str.