CSC300 / CSC402: Equals Operator and Equals Method [2/24]

In Java, == checks object identity on object types

• That is, the two operands refer to the same object
• More concretely: the two operands evaluate to the same address in memory

Unlike other languages (such as C++) this behavior cannot be changed.

Objects all have an equals method.

• The behavior of equals varies from class to class.
• The default method, defined in java.lang.Object, tests identity, just like ==
• Many of java's builtin classes override this default behavior to check value equality rather than object identity

The java.util.Objects class provides some handy utilities, like Objects.equals

• You can see the code in IntelliJ IDEA using Navigate > GoTo... There's a shortcut! On a Mac, you can use Cmd+RightClick. On Linux or Windows, you can use Ctrl+RightClick.

• Note:If you try navigating to the code and see something about class files decompiled by the FernFlower decompiler, let me know - we can get you set up to see the Java sources.