Check if defined php
- Check if constant defined php
- Check if function defined php
- Check if variable is defined php
- Check if property is defined php
- Check if define is defined php
- Check if array key is defined php
- Php check if defined constant exists
- Php check if class defined
- Php check if value defined
- Check if object is defined php
- Php check if defined variable exists
- Php check if defined exists
- Php check if constant defined