extend layout

Sorry, I got misunderstood.

> since renderSection ($sectionName) does not return any value

It means renderSection() returns null. Use if else statements in your layout properly.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper

Sorry, I got misunderstood.

> since renderSection ($sectionName) does not return any value

It means renderSection() returns null. Use if else statements in your layout properly.

renderSection() always return null: if it was used, it echo something then return (without explicit call to return); if it is not used, it is run return only

so, I can't do what you suggest...

Ahha, I got you! Sorry, again. You're correct.

> if a layout can define a default behavior that is used when the section is not defined in the view extension.

Therefore, the answer is "no, you can't".
A layout is not a view.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper

Ahha, I got you! Sorry, again. You're correct.

> if a layout can define a default behavior that is used when the section is not defined in the view extension.

Therefore, the answer is "no, you can't".
A layout is not a view.

it is a pity that this is not possible!

I hope it can be implemented in a future version. how can I suggest it?

anyway, thanks for the support