I am trying to generate a HashSet containing unique Employee instances. Uniqueness should be established based on the object properties. The problem is that I end up with having duplicates. Note that Employee class is provided by a framework, and it’s not possible to provide custom implementations for e…
Tag: equals
Which choice is better for generating equals() and hashCode() methods in Hibernate?
I create equals() and hashCode() methods in each Hibernate entity (if there is no inheritance) in my Java app. However, I am a little bit confused and wanted to be sure if I define it properly. Could you please clarify the following issues? In IntelliJ, when I use the “Generate” feature (via Alt +…
How do I check if two simple 2D arrays have the same 1D arrays? (order and repetitions doesn’t matter)
My main objective is to return if all elements, int[ ], of a 2D Array ,int[ ][ ], are present in another 2D Array. I already tried to use Arrays.deepEquals() but in this case, the order of the elements would matter and that’s not the purpose. Int[ ][ ] arrays wouldn’t be longer than 15, for exampl…
Compare two objects excluding some fields – Java
I need to compare two objects of the same class excluding some fields. How can i find if the two objects of the above class are equal excluding createdAt and updatedAt values? Since there are a lot of fields in this class, i don’t want to compare each of them one by one. Please don’t give AssertJ&…
How can UserDefined class be a key of hashmap if hashCode() & equals() return same value
I am trying to implement HashMap with UserDefined class as Key, i am successfull even when I implement both hashCode() (returns 0 for every object) & equals() (returns false for every object). My Code output:- Can anyone let me know the reason how it’s working Answer This is happening because equals…
Best instructions for null scenario in String approach [closed]
Closed. This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 2 years ago. Improve this question I want to hear opinions and arguments on this topic, I’m pretty…
problem with equals() method when used after toString() method
When I tried to take two strings as input to a function and check whether they are anagrams, I am getting the wrong output. I have written the following code. The sample input I have taken is s = “anagram” and t = “nagaram” . When checked, both the char arrays are printing the same val…
Why is casting in equals necessary?
I’m doing the Mooc course and it’s teaching us how to compare objects from made up classes like “Person” and see if they are equal to each other. They give us the following code: } For the equals method, I get that they compare using == first to check if it’s the same location. N…
The operator && is undefined for the argument type(s) boolean, String
I am trying to check if all the conditions below return a true and then validate, but the compiler fails saying: The operator && is undefined for the argument type(s) boolean, String I come from JS background an not Java, so any help would be appreciated. Answer Change to
Java – Why can’t I use charAt() to see if a char equals another?
I want to see if a character in my string equals a certain other char value but I do not know what the char in the string is so I have used this: But I get the error: But “g” == “h” seems to work and I know you can use ‘==’ with char types. Is there another way to