each() is deprecated in 7.2 and the notice appears once per call, which on a loop means once per iteration and a log file measured in megabytes.
// deprecated, and relies on the internal array pointer
while (list($key, $value) = each($array)) { /* ... */ }
// the replacement is the loop everyone else was already writing
foreach ($array as $key => $value) { /* ... */ }The translation is mechanical except where the internal pointer was load-bearing — code calling reset() or current() between iterations is relying on state that foreach does not share, and those need reading rather than replacing. Grep for it before the upgrade rather than after: the notice volume alone can fill a disk on a busy import.