What does this code mean (c++) ? years = y >= 18 ? y : 18; [duplicate]

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• How do I use the conditional operator? 6 answers

I was looking in my friends notes and I saw this code

 years = y >= 18 ? y : 18;

all what I know about the ? in c++ it's act like if statement

can I have some help with it ?

like how to write it with if