What is the best way to convert an int array from ascending order to descending order?

For example, how can I convert exArray1.1 to exArray1.2?

(exArray1.1)

example[0] = 1

example[1] = 2

example[2] = 3

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(exArray1.2)

example[0] = 3

example[1] = 2

example[2] = 1