Call arraysearch() function, and pass the key, and array keys as. I feel like im missing something obvious here. To find the index of a key in an array in PHP, you can use arraysearch() function. $evenAsciiOnly = array_filter( function($x), $arr) ī) A better way to build the character array from the string (and if so, how about the other direction?) $ascval = array_map('ord', $arr) //so i can do stuff like this $arr = stringToArray($s1) //$arr now has character array This is the best I've got function stringToArray($s) I mean, if you can index on it shouldn't you be able to iterate as well? It feels like there should be something better. Echoing data using foreach loop in codeigniter. ![]() How to convert resultarray() to result() object in codeigniter. Is it possible to get the index of foreach in view in codeigniter 0. E.g.: a > apples, b > bananas : then index(b) would return 1. php array pass by reference - assigning a duplicate value for the key gets discarded. Type casting/juggling didnt get me anywhere (put the whole string as one element of array), and the best solution I've found is simply using a for loop to construct the array. In the case of an array where the key does not match the index of the array element, I believe Alex would like to obtain the current index. So, while the examples given work for a typical usage, I'd rather not use an index at all if you can avoid it.Is there a nice way to iterate on the characters of a string? I'd like to be able to do foreach, array_map, array_walk, array_filter etc. at some point -when it overflows- the index will be the same for two different values). Here are the standard ways of writing the forEach Loop: array.forEach(callbackFunction) array.forEach(callbackFunction, thisValue) The callback function can accept up to three different arguments, though not all of them are required. Your foreach will be infinite: if you used an int (or long) index, you'll eventually overflow it (and unless you use an unchecked context, it'll throw an exception if you keep adding to it: even if you used unchecked, the index would be meaningless also. The first argument of an loop will be the actual array item, the second argument will be the index, and the third argument will be the full. So if you do: foreach(var row in InfiniteEnumerable()) The second argument passed into the callback you provide to the forEach method will be the current index the forEach loop is at, which is how you can get the index in a forEach loop. Take this example: public static IEnumerable InfiniteEnumerable() Its that simple This article was posted in Code, PHP Tutorials. For example, if you need to have the elements presented in ascending order by key, use the ksort function to rearrange the elements of the array in key sequence. The variable key will contain the key / index of the current item inside the foreach loop. ![]() In your example, you are using the ItemsSource of a DataGrid, so more likely your IEnumerable is just a list of objects (or DataRows), with a finite (and hopefully less than int.MaxValue) number of members, but IEnumerable can represent anything that can be enumerated (and an enumeration can potentially never end). For an array, foreach presents the elements of the array in the order that they were added to the array. An IEnumerable can be potentially infinite. The concept of an "index" is foreign to an IEnumerable. If the internal pointer points beyond the end of the elements list or the array is empty, key () returns NULL. you may want to check if it's directly convertible to a generic IEnumerable without having to call Cast(), but I'll make no such assumptions. According to the PHP documentation of key (): The key () function simply returns the key of the array element thats currently being pointed to by the internal pointer. 7.4.0 Instances of SPL classes are now treated like empty objects that have no properties instead of calling the Iterator method with the same name as this function. Your datatype is not clear from the question, but I'm assuming object since it's an items source (it could be DataGridRow). Either convert the object to an array using getmangledobjectvars() first, or use the methods provided by a class that implements Iterator, such as ArrayIterator, instead. otherwise, you may want to make the Cast outside your loop to convert it to an IEnumerable. In your case, since your IEnumerable is not a generic one, I'd rather use the foreach with external index (second method). if you are sure your enumerable has less than int.MaxValue elements (or long.MaxValue if you use a long index), you can:ĭon't use foreach, and use a for loop, converting your IEnumerable to a generic enumerable first: var genericList = list.Cast() įor(int i = 0 i ().Select((r, i) => new )) You can't, because IEnumerable doesn't have an index at all.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |