Why headers sent error occur in action in controller in yii2?

Question

There is an error saying, headers are already sent, showing that print_r occuring the error, but in tutorial the print_r's array appears before navbar at the top of web page

class PostController extends AppController
{
    public function actionTest()
    {
        $names = ['Ivanov', 'Petrov', 'Sidorov'];

        print_r($names);

        return $this->render('test');
    }

}

you are trying to output some data before header redirection. that's cause the issue. remove `print_r($names);` and you will good to go — Alive to die - Anant, Sep 10 '18 at 04:58
Whenever you want to check/print your data (for testing purpose) you should put a `die();` before rendering the view. — Gru, Sep 10 '18 at 06:50
@Gru `die()` will break framework flow - you should avoid using `echo`/`print_r` in the first place. — rob006, Sep 10 '18 at 07:46
welll if i have to check an `array` or `data` i would `print_r();` and then `return;` the next line. — Muhammad Omer Aslam, Sep 10 '18 at 09:20

score 1 · Answer 1 · answered Sep 10 '18 at 07:02

YOu shuold not output values with echo, print_r or var_dump .. before return

class PostController extends AppController
{
  public function actionTest()
  {
    $names = ['Ivanov', 'Petrov', 'Sidorov'];


    return $this->render('test');
  }

}

in your case remove print_r($names);

Why headers sent error occur in action in controller in yii2?

1 Answers1