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Under what circumstances given a correct implementation of hashCode and equals() can the following code return false?
myLinkedHashMap.containsKey(myLinkedHashMap.keySet().iterator().next())
Most likely scenario I can think of would be even though
hashCodeis “deterministic”, it may be based on mutable fields. If you change the fields used to computehashCodeafter it’s put in theMap, then you won’t be able to find it anymore.Edit: should clarify you ‘usually’ won’t be able to find it anymore. Occasionally it will still work since two numbers can still rehash into the same bucket. This, of course, only adds to the confusion when it happens!