Check if is string php
- Check if string is php email
- Check if variable is string php
- Check if value is string php
- Check if var is string php
- Check if there is string php
- Check if string is empty php
- Check if string is number php
- Check if string is json php
- Check if string is date php
- Check if string is int php
- Check if string is url php
- Check if string is base64 php
- Check if string is numeric php
- Check if string is float php
- Check if string is null php