java - Intersection of two sets -

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• efficiently finding intersection of variable number of sets of strings 7 answers

is easy way intersection of 2 sets? have:

    set<long> set1 = {1,2,3}     set<long> set2 = {2,3,4} 

and looking or method like:

    set<long> intersection = new hashset<>();     intersection.intersect(set1, set2); 

and intersection.tostring() produce me set contains {2,3}

you can use retainall().

note modify 1 of collections might want create copy first.