extend

问题 Regarding my post here: problems when extending a PHP Class What's the best solution? And why? $query = $this->Execute("SELECT * FROM $table"); $total = $this->NumRows($query); Or $query = DBManager::Execute("SELECT * FROM $table"); $total = DBManager::NumRows($query); Or $query = parent::Execute("SELECT * FROM $table"); $total = parent::NumRows($query); 回答1: When you extend a class, the child class can call all the public and protected methods and properties of the parent class in addition

问题 I am current using the below code snippet i found on stackxchg to delete rows that whereby there is no numeric value in column A. This works however it is gruesomely slow for a sheet with 5000 rows. Is there any way I can get this thing to go faster? The concept is, I have some rows that will kick out dates only if a criteria is met, and a chart will be generated using the dates in this column. I would like the chart range reference to change with the rows, but this is tough since there are

问题 According to Douglas Crockford I could use something like http://javascript.crockford.com/prototypal.html (with a little bit of tweaking)... but I am interested in jQuery way of doing it. Is it good practice using $.extend ? I have 4 classes : var A = function(){ } A.prototype = { name : "A", cl : function(){ alert(this.name); } } var D = function(){} D.prototype = { say : function(){ alert("D"); } } var B = function(){} //inherits from A B.prototype = $.extend(new A(), { name : "B" }); var C

问题 I'm trying to create an application on Symfony2 with Doctrine 2 entities. My problem is that I should have a main application which contains the mainly used functions and other applications which are gonna extend it on need. For example i have a UserInterface and also a User which implements UserInterface in the main App. All the other applications should be able to use this User, but in case one of the apps needs to add more properties to this User he is able to override the user class

问题 I have this array of dictionaries: var dicts = [["key1": "value1", "key2": "value2"], ["key1": "value3", "key2": "value4"]] How should I extend Array so that I have this function: dicts.values(of: "key1") // result: ["value1", "value3"] I try this: extension Array where Iterator.Element == [String: Any] { // ERROR! func values(of key: String) -> [Any]? { var result: [Any]? for value in self { let val = value as! Dictionary<String, Any> for k in val.keys { if k == key { if result == nil {

问题 This might be a silly question, but I'm struggling on how to make my class extend 2 classes at the same time. I'm trying to make a SERVICE that uses ListActivity. How could I do that? 回答1: Java or android Doesn't Support Multiple Inheritance 回答2: I assume you are coding in the Java programming language . Then the simple answer is: You don't. Java does not support deriving from multiple classes. Make your ListActivity contain a Service . class MyService extends Service{ ... } class MyList

问题 I extended the User model in django to include several other variables, such as location, and employer. Now I'm trying to create a form that has the following fields: First name (from User) Last name (from User) Location (from UserProfile, which extends User via a foreign key) Employer (also from UserProfile) I have created a modelform: from django.forms import ModelForm from django.contrib import auth from alert.userHandling.models import UserProfile class ProfileForm(ModelForm): class Meta:

问题 I need to make an exisitng web application compatible with IE7. The code uses element.hasAttribute extensively and IE7 has issues with this method. Object doesn't support property or method 'hasattribute' I am trying to check in the code if an input element has the hasAttribute method defined and if not, I am trying to add it to all input elements. //create an input element variable << works fine var myInput = document.createElement("input"); //see if it has the 'hasAttribute' method <<

问题 I'm having a bit of a problem grasping something - I might be going about this completely wrong. I am trying to create a class which extends ArrayList but has several methods which increase the functionality (at least for the program I am developing.) One of the methods is a findById(int id), which searches each ArrayList object for a particular id match. So far it's working, but it won't let me do for (Item i : this) { i.getId(); } I don't understand why? Full code: public class

问题 I am trying to extend my left sidebar so that it spans the length of the page (or the container DIV). I tried setting the height of the container to 100% and then the height of the sidebar to 100%, but that did not work. Here is my coding: div#container { overflow: hidden; margin-left: auto; margin-right: auto; margin-top: 0px; padding-bottom: 10px; width: 880px; height: 100%; text-align: left; } div#left { float: left; width: 280px; height: 100%; padding: 4px; background: #F1D7A5; } And here