Why are the variables not being declared in the program given below?

Question

I'm a beginner and learning php. Yet I'm unable to understand why the session variables remain undefined inside the php code... Please help me understand... 🙏

https://code.sololearn.com/wFuqliFmpNQ8/?ref=app

Answer 1

AND - both operand should be true inorder to get true as result

OR - results in true even if only one of the operand is true

NOT - reverse whatever the result is, true is false and false is true.

Answer 2

Yes, you're correct and I know about this concept... but actually the problem is that in this program $result, $num1 and $num2 remain undefined for the php code. However their values have been defined under the form tag. This is what I'm not getting. 🤷‍♀️