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The sort() operator takes an optional argument and returns an array that is the original array sorted according to the following criteria:

• If the argument is empty or the string "default", the array will be sorted in ascending order using the cmp operator.
• If the argument is the string "reverse", the array will be sorted in descending order using the cmp operator.
• If the argument is the string "numeric", the array will be sorted in ascending order using the <=> operator.
• If the argument is the string "ciremun" ("numeric" backwards), the array will be sorted in descending order using the <=> operator.
• If the argument is a function, the function will be used to perform pair-wise comparisons of the members of the array for purposes of doing the sort. The function must take two arguments and return -1, 0, or 1 depending on whether the first argument is less than, equal to, or greater than the second.

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