Java HashMap: hashcode() and equals() method Lets override default implemenation of hashcode() and equals(): Lets put this Country objects in hashmap: hashcode() and equals() contracts: equals(): hashcode(): Key
publicclassObjectDemo{publicstaticvoidmain(String[]args){// get an integer, which is an objectIntegerx=Integer.valueOf(50);// check if x is equal with same objectSystem.out.println(""+x.equals(x));}} Output Let us compile and run the above program, this will produce the following res...
2. ThrowsNullPointerException Theequals()does not supportnullargument and throwsNullPointerException. Stringstr1="alex";Assertions.assertThrows(NullPointerException.class,()->{str1.contains(null);}); 3. Only Case-sensitive Comparisons The following Java program demonstrates thatequals()method does the...
This is one of the tricky Java interview questions, which some of you might have encountered. There is a very subtle difference betweengetClass()and instanceof operator, which can cause potential issues with respect to theequals()method. Coming to the point, the key difference between them is...