I have these two object which have all equal fields.
Why does obj1.equals(obj2) return false?
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Johnny Bones
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Elad Benda2
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1Have a read of http://stackoverflow.com/questions/767372/java-string-equals-versus – Chris K Jul 03 '14 at 14:13
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2Can you please read docs of equal method in Object class ? – Suresh Atta Jul 03 '14 at 14:13
3 Answers
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This is the default behaviour of equals(comparing references). So, if == returns false on Object, .equals() returns false as well. Unless you have overidden equals().
TheLostMind
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if these are two instances of the same class with only int Strings and a float - I don;t think i need to override the equals. no? – Elad Benda2 Jul 03 '14 at 14:16
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1You do if you want it to work the way you expect it to. – Reinstate Monica -- notmaynard Jul 03 '14 at 14:18
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2 *instances* have 2 *separate* locations in memory. So, `==` returns false (compares references), so does `equals()`. – TheLostMind Jul 03 '14 at 14:18
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If you don't override equals method, then when you are doing
obj1.equals(obj2)
It is comparing the values as displayed in your image.
"com.waze.testing.data.Pin@4355".equals("com.waze.testing.data.Pin@4361")
which will returns false as per your result.
vikiiii
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if these are two instances of the same class with only int Strings and a float - I don;t think i need to override the equals. no? – Elad Benda2 Jul 03 '14 at 14:17
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updated the answer. @USER1065869 No,you still need to override the equal instance, else it will compare the instance which is unequal in this case. – vikiiii Jul 03 '14 at 14:29
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Did you override .equals()? If not, it is using Object.equals() which only returns true if they are the exact same instance.
Jesse
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if these are two instances of the same class with only int Strings and a float - I don;t think i need to override the equals. no? – Elad Benda2 Jul 03 '14 at 14:17
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1@user1065869: Yes, you do. The default implementation of `equals()` compares the *references*. So unless they're the same instance of the object, they're not equal. To change that logic, you need to override the method. – David Jul 03 '14 at 14:18