你的函数在同一个类中，你可以在另一个函数中使用$ this调用一个函数，如其他答案中指出的那样

  class myclass {

 public $ var1 = 121; 
 public function foo（$ postid）{
 echo $ postid; 

 public function bar（）{
 $ this-> foo（$ this-> var1）; 
} 
} 
 $ objectmyclass = new myclass（）; 
 $ objectmyclass-> bar（）; 
 

OR

  class myclass {

 public $ var1 = 122; 
 public function foo（$ postid）{
 echo $ postid; 
} 
公共功能栏（$ postid）{
 $ this-> foo（$ postid）; 
} 
} 
 $ objectmyclass = new myclass（）; 
 $ objectmyclass-> bar（$ objectmyclass-> var1）; 
 

这两种方法都可以执行函数foo中的语句
希望这有助于

I want to pass variable ($q_view) from a function q_view_main to a function sidebar. Also searched *** for solution but dont understand it.

Both functions are in same class.

function main()
{       
    $content=$this->content;

    $this->main_parts($content);

    $this->suggest_next();

    $this->widgets('main', 'bottom');

    $this->main_sidebar();
}
function main_sidebar()
{
    $content=$this->content;
    $main_class = ((!empty ($content['widgets']['main']['high'])) ? 'twelve' : 'nine');
    if (!empty ($content['widgets']['main']['high'])){                              
        $this->output('<DIV class="main-sidebar three columns">', '');
        $this->post_tags($q_view_for_sidebar, 'qa-q-view'); //want 
        $this->widgets('main', 'high');

        $this->output('</DIV>');
    }
}
function main_parts($content)
{
    foreach ($content as $key => $part) {
        $this->set_context('part', $key);
        $this->main_part($key, $part);
    }
}
function main_part($key, $part)
{
    if (strpos($key, 'custom')===0)
        $this->output_raw($part);

    elseif (strpos($key, 'form')===0)
        $this->form($part);

    elseif (strpos($key, 'q_list')===0)
        $this->q_list_and_form($part);

    elseif (strpos($key, 'q_view')===0)
        $this->q_view($part);

    elseif (strpos($key, 'a_form')===0)
        $this->a_form($part);

    elseif (strpos($key, 'a_list')===0)
        $this->a_list($part);

    elseif (strpos($key, 'ranking')===0)
        $this->ranking($part);

    elseif (strpos($key, 'message_list')===0)
        $this->message_list_and_form($part);

    elseif (strpos($key, 'nav_list')===0) {
        $this->section(@$part['title']);        
        $this->nav_list($part['nav'], $part['type'], 1);
    }
}
function q_view_main($q_view)
{           
    $this->q_view_stats($q_view);           
    $this->post_meta_author($q_view, 'qa-q-view');
    $this->q_view_content($q_view);
    $this->q_view_extra($q_view);
    $this->q_view_follows($q_view);
    $this->q_view_closed($q_view);


    $this->post_tags($q_view, 'qa-q-view');         
    $this->post_meta_other($q_view, 'qa-q-view');
    $this->q_view_buttons($q_view);
    $this->c_list(@$q_view['c_list'], 'qa-q-view');
    $this->output('</DIV>');

}

If both of your function are residing in the same class you can call a function inside another function using $this as pointed in other answers

class myclass{

public $var1 = 121;
    public function foo($postid){
        echo $postid;
    }
    public function bar(){
        $this->foo($this->var1);
    }
}
$objectmyclass = new myclass();
$objectmyclass->bar();

OR

class myclass{

public $var1 = 122;
    public function foo($postid){
        echo $postid;
    }
    public function bar($postid){
        $this->foo($postid);
    }
}
$objectmyclass = new myclass();
$objectmyclass->bar($objectmyclass->var1);

both ways you will be able to execute the statements inside the function foo hope this helps