Menu
If I have two objects o1 and o2, and we know that
id(o1) == id(o2) returns true.
Then, does it follow that
o1 == o2 Or is this not always the case? The paper I'm working on says this is not the case, but in my opinion it should be true!
566
If the two objects have the same values, equals() will return true . In the second comparison, equals() checks to see whether the passed object is null, or if it's typed as a different class. If it's a different class then the objects are not equal.
The equals() method of the Object class compare the equality of two objects. The two objects will be equal if they share the same memory address. Syntax: public boolean equals(Object obj)
The == operator compares the value or equality of two objects, whereas the Python is operator checks whether two variables point to the same object in memory. In the vast majority of cases, this means you should use the equality operators == and != , except when you're comparing to None .
Java determines equality with the equals(Object o) method - two objects a and b are equal iff a. equals(b) and b. equals(a) return true . These two objects will be equal using the base Object definition of equality, so you don't have to worry about that.
Not always:
>>> nan = float('nan') >>> nan is nan True or formulated the same way as in the question:
>>> id(nan) == id(nan) True but
>>> nan == nan False NaN is a strange thing. Per definition it is not equal nor less or greater than itself. But it is the same object. More details why all comparisons have to return False in this SO question.
185
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
