interface member variable

i would like to know about interface member variables. I was reading as

Interfaces may have member variables, but these are implicitly public, static, and final- in other words, interfaces can declare only constants, not instance variables that are available to all implementations and may be used as key references for method arguments for example.



i am not clear on what it mean by ' as key references for method arguments'. Thanks in advance
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gudii9Asked:
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for_yanConnect With a Mentor Commented:
Think about some say SwingConstants interface or something like that when they have constants like ScrollbarPoloicy.ALWAYS_PRESENT or something like that. The set methid actually need sinmpole integer, but for you easierbto remememver this integrer is given such mname and tyou use it is setrPoloicy method. You'll nmever need to change integer - so it isa final , it is all rthe way constant for all instances, and it is desugned to be used as parameter of tge methods.
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rumi78Commented:
gudii9 what a book you are reading ... :)

'as key references for method arguments' may be understand as 'may be used' :)
the example was about:
method(Interface.CONSTANT);
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Kevin CrossChief Technology OfficerCommented:
This question has been classified as abandoned and is closed as part of the Cleanup Program. See the recommendation for more details.
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