php - how I use flash message in yii2? -

how add flash message site using related controller please explain step step i'm new php.

i use yii2 framework build site , need print flash message in index page using create controller.

currently question broad, here basic usage:

1) can set in controller that:

\yii::$app->session->setflash('flashmessage', 'hello world!'); 

2) can display in view so:

echo \yii::$app->session->getflash('flashmessage'); 

optionally can check existence with:

\yii::$app->session->hasflash('flashmessage'); 

official docs:

• session
• setflash()
• hasflash()
• getflash()

there more methods working flashes, can see in official docs.

also advanced template provides useful widget alert integrated boostrap 3:

\yii::$app->session->setflash('error', 'this error message');  ...  echo alert::widget();