In MAMP by default error_reporting is turned off. This is how you can enable all errors!

1. Find your ‘MAMP’ directory in ‘Applications’

2. Find ‘conf’ and open it up..

3. Open up php4 or php5 (depending on your enabled version)

4. Line 270 should be something like this:
error_reporting = E_ALL

5. Line 277 will be:
display_errors = Off

Change this to:
display_errors = On

6. Restart servers

Ready to go !!