Object.equals
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Syntax
public boolean equals( Object obj )
Parameters
- obj
the reference object with which to compare.
Returns
true if this object is the same as the obj argument; false otherwise.
Description
Compares two Objects for equality.
The equals method implements an equivalence relation:
- It is reflexive: for any reference value x, x.equals(x) should return true.
- It is symmetric: for any reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
- It is transitive: for any reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
- It is consistent: for any reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false.
- For any reference value x, x.equals(null) should return false.
The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any reference values x and y, this method returns true if and only if x and y refer to the same object (x==y has the value true).