What does ? mean when declaring a type in javafx?

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I'm just curious what does this do

Java

<?>

in this code?

Java

node instanceof ComboBox<?>

I tried replacing it with

Java

node instanceof ComboBox<String>

but eclipse warns me that

Java

Type Node cannot be safely cast to ComboBox<String>

What I have tried:

I tried to search this already but found no answer or maybe I'm just searching the wrong keywords. Anyway, big thanks for any future clarifications and help.

Posted 1-May-22 19:21pm

lelouch_vi 2

Updated 1-May-22 19:37pm

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OriginalGriff · Accepted Answer · 2022-05-01T19:37:00

Solution 1

It's called an Unbounded Wildcard[^]

Posted 1-May-22 19:37pm

OriginalGriff

Comments

CPallini 2-May-22 2:42am

5.

lelouch_vi 2 2-May-22 8:59am

what is 5.?

CPallini 2-May-22 9:30am

I gave him 5 stars.
You are free to give him 5 stars as well.

lelouch_vi 2 2-May-22 21:24pm

@CPalini oh okay. I just thought that you were referring to a line number or anything within the link given by OriginalGriff. Silly me anyway yeah 5 stars for this.

OriginalGriff 2-May-22 9:31am

If you look at where it says "Solution 1" above, you will see five stars on the right hand side. These are a "voting system" where 1 star means "bad answer" and 5 stars means "excellent answer".
Carlo was just saying "well done!" to me for the answer I gave you, is all.

lelouch_vi 2 2-May-22 9:09am

@OriginalGriff there you go thanks a lot! Now I know what it is called. cheers!

OriginalGriff 2-May-22 9:31am

You're welcome!