Why ? Is used in the condition?

Question

Please tell me the reason

Answer 1

I'm still not now how to solve ? Sign

Answer 2

https://www.sololearn.com/discuss/2042939/?ref=app

Answer 3

(Condition)?(statement 1) : (statement 2)
First of all the condition before ? Execute if it's true then statement 1 will br followed and if the condition is wrong then the statement 2 will be followed