Are there any differences between php 7.0 and 7.1 when handling undefined variables?

[harriett...@gmail.com]

I have a php app that's been working for months. Then all of a sudden it starts to render Internal Server 500 errors when encountering undefined variables in code. I had to use isset() to check the variables first.

I also found that the app server is installed with two versions of PHP - 7.0 and 7.1. There are two handlers mapped to *.php files. When I run phpinfo(), it's version 7.1 info displays. I wonder if there is any differences between how version 7.0 and 7.1 handle undefined new variables.

Any ideas? Many thanks.

[Angel]

Always add a value to a variable. Do not leave a variable undefined, it can produce serious problems running the app.