Will alarm ring if phone is on silent mode, mute or flight mode?

Hi,
Will alarm ring if my phone is on silent mode, on mute or flight mode?

Yes, alarm will ring even if your phone is on silent mode, mute mode or flight mode.

This works at least on recent Android phones.

On iPhone, alarm will also ring if your phone is on Silent mode or in Do Not Disturb mode. The built-in clock app is designed to override the settings.