java - Why String.contains with empty String returns true? -


when work code found this,

 string mystring1="foo";  string mystring2="";           if(mystring1.contains(mystring2)){               system.out.println("am here");           }           else{               system.out.println("am not here");           }

it print am here why? please 1 me find this.

it same principle empty set subset of every possible set.


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