field

问题 This question already has answers here : Remove blank attributes from an Object in Javascript (31 answers) Closed 2 years ago . Is there a clean way to remove undefined fields from an object? i.e. > var obj = { a: 1, b: undefined, c: 3 } > removeUndefined(obj) { a: 1, c: 3 } I came across two solutions: _.each(query, function removeUndefined(value, key) { if (_.isUndefined(value)) { delete query[key]; } }); or: _.omit(obj, _.filter(_.keys(obj), function(key) { return _.isUndefined(obj[key]) }

问题 I'm trying to re-order 2 custom checkout fields added with the help of woocommerce_checkout_init filter, just that when I apply woocommerce_checkout_fields filter to re-order fields, it doesn't recognize them and they are null . I think it's because the filter woocommerce_checkout_init goes after woocommerce_checkout_fields . How Can I solve this? Here is my code: add_action( 'woocommerce_checkout_init', 'wc_add_confirm_email_checkout', 10, 2 ); function wc_add_confirm_email_checkout(

问题 In MySql's interpreter, it's very easy to dump a table to the screen along with its field names. There seems to be no simple way to export a table to a tab-delimted or CSV outfile including its column headers. I'm trying to do this using only SQL or the Linux command line, without writing a program in another language. Thank you 回答1: Piping the query to the commandline client outputs a tab separated list with the column names as the first line $ echo "select * from surveys limit 5" | mysql

问题 Is there a simpler function to something like this: if (isset($_POST['Submit'])) { if ($_POST['login'] == "" || $_POST['password'] == "" || $_POST['confirm'] == "" || $_POST['name'] == "" || $_POST['phone'] == "" || $_POST['email'] == "") { echo "error: all fields are required"; } else { echo "proceed..."; } } 回答1: Something like this: // Required field names $required = array('login', 'password', 'confirm', 'name', 'phone', 'email'); // Loop over field names, make sure each one exists and is

问题 We're often told we should protect encapsulation by making getter and setter methods (properties in C#) for class fields, instead of exposing the fields to the outside world. But there are many times when a field is just there to hold a value and doesn't require any computation to get or set. For these we would all do this number: public class Book { private string _title; public string Title { get{ return _title; } set{ _title = value; } } } Well, I have a confession, I couldn't bear writing

问题 I would like to allow a field in a form I have to allow only file names to be accepted. File names looks like this: 431714620407606949.jpg 18 digits [dot] jpg/gif/ico/png/tiff Also I would like the field to accept multiple file name entries, so I want it to be like this: 431714620407606949.jpg,431714620407674859.jpg,837593620407606949.jpg 回答1: This should do it: http://regexr.com?353i8 ( /([\d]{18}\.)(jpg|png|gif)/g ) This site will help you with your regex' 回答2: The following will match

问题 I have a mysql table called districts where all the districts and their id's are stored. I have another table called tbl_units where unit details such as office_address , office_district , factory_address , factory_district are saved. Now if want to get the names of the districts from their id's by JOIN ing the two tables, how should I write the query ? Because SELECT u.*, d.district_name FROM tbl_unit_details as u, tbl_districts as d WHERE u.unit_id = '$unit_id' AND u.district_id = d

问题 This question will undoubtedly be difficult to answer and ask in a way that makes sense but I'll try my best: I have a form which uses PHP to display certain sections of the form such as: <?php if ($_SESSION['EnrType'] == "Individual") { display only form information for individual enrollment } ?> and <?php if ($_SESSION['Num_Enrs'] > 6) { display only form information for 7 total members enrollment } ?> In each form piece, unique information is collected about each enrollee but the basic

问题 I am using Swift for an iOS app. I need to store a DateComponents object as a field in CloudKit. How would I do that? So far I think I need to set the CloudKit field to type Bytes, and convert the DateComponents object to a Data object. Looking at the documentation for the Data class, I can't figure out how to initialize the Data object. I have no idea how to use the UnsafeBufferPointer used in one of the initializers. The following code gives a runtime error: newRecord.setObject(

问题 I heard there is a field extension method in framework 4 that permits one to receive null values from a datareader, without having to go through the process of first testing if not null then ... etc. There's information about the extension method here (MSDN), but i don't know how to use it in code (am relatively new to .net and never used extension methods before). Would appreciate if anyone can give an example. This is what i tried to implement, but it returns an error when a dbnull is