ArrayIterator::uksort

    (PHP 5 >= 5.2.0, PHP 7, PHP 8)

    ArrayIterator::uksort — Sort by keys using a user-defined comparison function

    Description

    publicArrayIterator::uksort(callable$callback): true

    This method sorts the elements by keys using a user-supplied comparison function.

    Note:

    If two members compare as equal, they retain their original order. Prior to PHP 8.0.0, their relative order in the sorted array was undefined.

    Parameters

    callback

    The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.

    callback(mixed$a, mixed$b): int
    Caution

    Returning non-integer values from the comparison function, such as float, will result in an internal cast to int of the callback's return value. So values such as 0.99 and 0.1 will both be cast to an integer value of 0, which will compare such values as equal.

    Return Values

    Always returns true.

    Changelog

    VersionDescription
    8.2.0 The return type is true now; previously, it was bool.

    See Also

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