What is hash code and equals contract ?

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Accepted Answer

Hash code and equals contract are used to ensure consistency and correctness in object comparison.

Hash code is a unique integer value assigned to an object based on its contents.
Equals method is used to compare two objects for equality.
Hash code and equals must be consistent with each other, i.e., if two objects are equal, their hash codes must also be equal.
If two objects have the same hash code, it does not necessarily mean that they are equal.
Overriding hash code and equals methods is important when using objects as keys in hash-based collections like HashMap.
Example: If two Person objects have the same name and age, they should be considered equal and have the same hash code.
Example: If two String objects have the same value, they should be considered equal and have the same hash code.

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