array-reduce

问题 I'm trying to get counts of array values greater than n . I'm using array_reduce() like so: $arr = range(1,10); echo array_reduce($arr, function ($a, $b) { return ($b > 5) ? ++$a : $a; }); This prints the number of elements in the array greater than the hard-coded 5 just fine. But how can I make 5 a variable like $n ? I've tried introducing a third argument like this: array_reduce($arr, function ($a, $b, $n) { return ($b > $n) ? ++$a : $a; }); // ^ ^ And even array_reduce($arr, function ($a,

问题 Evolving from Javascript, spliced FileReader for large files with Promises, how?, which showed me how a Promise can also resolve a function, now I am stuck with the same but inside an Array.reduce function. The goal is that I want to upload a file (which already does) within an array, where each array item (a file) is uploaded sequentially (i.e. controlled through promises). Then, I understand that the answer is somehow in http://www.html5rocks.com/en/tutorials/es6/promises/?redirect_from

问题 var developers = [ { name: "Joe", age: 23 ,overallLevel: "high"}, { name: "Sue", age: 28 ,overallLevel: "advanced" }, { name: "Jon", age: 32 ,overallLevel: "high" }, { name: "Bob", age: 24 ,overallLevel: "high" }, { name: "Bob", age: 20 ,overallLevel: "advanced" } ] Need count of overallLevel in the mentioned array using array.reduce() [high:3, advanced:2] 回答1: You could just count them with an object. var developers = [{ name: "Joe", age: 23, overallLevel: "high" }, { name: "Sue", age: 28,

问题 After implementing database queries, I am getting the multi-dimensional array below. Two Dimensional Array Array ( [0] => Array ( [t1] => test1 ) [1] => Array ( [t2] => test2 ) [2] => Array ( [t3] => test3 ) [3] => Array ( [t4] => test4 ) [4] => Array ( [t5] => test5 ) ) but I want to convert it to a single dimensional array, like the format below. One Dimensional Array Array ( t1 => test1 t2 => test2 t3 => test3 t4 => test4 t5 => test5 ) Please help me to do so 回答1: I think you can use array

问题 I'm sure this question has been asked before, my apologies for not finding it first. The original array: [0] => Array ( [categoryId] => 1 [eventId] => 2 [eventName] => 3 [vendorName] => 4 ) [1] => Array ( [categoryId] => 5 [eventId] => 6 [eventName] => 7 [vendorName] => 8 ) [2] => Array ( [categoryId] => 9 [eventId] => 10 [eventName] => 11 [vendorName] => 12 ) My hoped for result out of: print_r(get_values_from_a_key_in_arrays('categoryId', $array)); [0] => 1 [1] => 5 [2] => 9 I'm just