opCmp
Let’s discuss the opCmp function in this lesson.
We'll cover the following
opCmp
for class objects
This operator is used when sorting class objects. opCmp
is the function that gets called behind the scenes for the <
, <=
, >
, and >=
.
This operator must return a negative value when the left-hand object is before, a positive value when the left-hand object is after, and zero when both objects have the same sorting order.
Warning: The definition of this function must be consistent with
opEquals()
; for two objects thatopEquals()
returnstrue
,opCmp()
must return zero.
Unlike toString
and opEquals
, there is no default implementation of this function in Object
. If the implementation is not available, comparing objects for sort order causes an exception to be thrown:
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