I am running a PHP script, and keep getting errors like:
Notice: Undefined variable: my_variable_name in C:\wamp\www\mypath\index.php on line 10
or
Notice: Undefined index: my_index C:\wamp\www\mypath\index.php on line 11
Line 10 and 11 looks like this:
What do these errors mean?
Why do they appear all of a sudden? I used to use this script for years and I've never had any problem.
What do I need to do to fix them?
This is a General Reference question for people to link to as duplicate, instead of having to explain the issue over and over again. I feel this is necessary because most real-world answers on this issue are very specific.
Related Meta discussion:
What can be done about repetitive questions?
Do “reference questions” make sense?