How to overwrite the value of a variable in config/params.php from a program?

Question

Yii

Hello,
How can I overwrite the value of a variable in config/params.php from a program?
Why Yii::$app->params[ 'test' ] = 'new value'; does not work?

Answer 1

Why Yii::$app->params[ 'test' ] = 'new value'; does not work?

works, do an experiment:

Yii::$app->params[ 'test' ] = 'новое значение'; 
echo Yii::$app->params[ 'test' ]; //выведет  'новое значение'

If it does not display, then write what it outputs and whether there are errors, after including all php errors

Answer 2

I do the following: I assign a new value to the test variable like this: Yii::$app->params[ 'test' ] = 'new value'; then I open the config/params.php file and there is the old value...

Here is a hint how to do it. Written for yii1, but easy to convert to yii2