note 127680 added to function.range

While it appears just like a convenient way to avoid the boilerplate of for(), beware that this is not an iteration operator, despite its similarity to other languages which do have virtual iterators. Instead it is a literal array-filling operator, just like array_fill()! Use of range() for generating a simple loop tends to be a code smell, and especially where the range values are variable, it should probably be rejected in code review with a note to replace with for(). In particular, it is unsafe to do things like: // Sanitize user input. $max = intval($userInputMax); // Loop over the range. foreach(range(1, $max)) { ... do stuff ... } If the user enters a large value like "1e9", this won't just loop for a long time: it'll also allocate a gigabyte, then fill it with a range of incrementing integers. This often results in a segfault. Instead, avoid the array-allocation overhead with the faster and more idiomatic: for ($i = $min; $i <= $max; $i += $step) {} Equally, I've debugged production code which did the following, which takes several minutes with a $max like 1e9, and will segfault if it's much larger than that (even with values well below 2^32!): $numItems = count(range($min, $max, $step)); This can instead be rewritten in a more secure, idiomatic and performant way, which takes just microseconds and can also safely handle vastly larger numbers: $numItems = ($max - $min) % $step; ---- Server IP: 45.112.84.4 Probable Submitter: 185.85.3.173 (proxied: 47.221.215.25) ---- Manual Page -- https://php.net/manual/en/function.range.php Edit -- https://main.php.net/note/edit/127680 Del: integrated -- https://main.php.net/note/delete/127680/integrated Del: useless -- https://main.php.net/note/delete/127680/useless Del: bad code -- https://main.php.net/note/delete/127680/bad+code Del: spam -- https://main.php.net/note/delete/127680/spam Del: non-english -- https://main.php.net/note/delete/127680/non-english Del: in docs -- https://main.php.net/note/delete/127680/in+docs Del: other reasons-- https://main.php.net/note/delete/127680 Reject -- https://main.php.net/note/reject/127680 Search -- https://main.php.net/manage/user-notes.php