php - Accessing variables within a function defined in another function?

问题

I'm trying to get variables that I defined while in a function from another function I called in that function, example:

$thevar = 'undefined';
Blablahblah();
echo $thevar; (should echo blaaah)
function Blahedit(){

     echo $thevar; (should echo blah)
     $thevar = 'blaaah';

}
function Blablahblah(){

     global $thevar;
     $thevar = 'blah';
     Blahedit();

}

I want to know if there's another way of doing this without passing down params to Blahedit(), get_defined_vars gives me vars within the function not $thevar... and calling global $thevar will just give me the previous unedited version.

Please help ):

回答1:

You can use this: http://php.net/manual/en/reserved.variables.globals.php

or better have a look at oop

http://php.net/manual/en/language.oop5.php http://php.net/manual/en/language.oop5.basic.php

回答2:

You can pass the variables as a reference parameter (shown below), encapsulate your code in a class and use your variable as class attribute or let the functions return the changed variable.

$thevar = 'undefined';
Blablahblah($thevar);
echo $thevar; 

function Blahedit(&$thevar){
     echo $thevar;
     $thevar = 'blaaah';
}

function Blablahblah(&$thevar){
     $thevar = 'blah';
     Blahedit($thevar);
}

Using globals inside functions is considered to be a bad practice. However, passing a lot of variables by reference also is not good style.

If you want to get your code to work the way it is, you have to add a global $thevar to your edit function:

function Blahedit(){
     global $thevar;
     echo $thevar; (should echo blah)
     $thevar = 'blaaah';
}

回答3:

Just global $thevar inside blahedit.

function Blahedit(){
    global $thevar;
    echo $thevar; //(should echo blah)
    $thevar = 'blaaah';

}

来源：https://stackoverflow.com/questions/14082589/php-accessing-variables-within-a-function-defined-in-another-function

标签

php

function

variables