methods

问题 I am trying to complete the Ruby on Rails Tutorial by Michael Hartl and I am stuck on Chapter 8. I am getting the same two errors when I run my tests: NoMethodError: undefined method remember_token=' ActionView::Template::Error: undefined method find_by_remember_token' I am very new to coding and programming so I'm not sure exactly what to post so people can help with my question. I feel like I've defined both :remember_token and find_by_remember_token. I've included each of the instances

问题 I'm practicing some work from my java book and I'm having an issue with getting a method to use a variable for a calculation. Please note that this is a work in progress and I'm only trying to get it to use the circleArea method to calculate the area of a circle at the moment. Here is the necessary code: public class Geometry { public static void printMenu() { System.out.println("This is a geometry calculator\nChoose what you would like to calculate" + "\n1. Find the area of a circle\n2. Find

问题 This question already has answers here : Is there a way to check if a function exists within a class? (3 answers) Check if method exists in the same class (4 answers) Closed 9 months ago . I want to use some code only if the method getProductgroup exists. My first approach: if(isset($item->getProductgroup())){ $productgroupValidation = 0; $productgroupId = $item->getProductgroup()->getUuid(); foreach($dataField->getProductgroup() as $productgroup){ $fieldProductgroup = $productgroup->getUuid(

问题 I have a jsp file in which I have a form. It shows data about an "account" data structure we have. There's a button to remove the data from that data structure. <form action="removeThisData.html" method="post"> ... blah blah blah ... <input type="submit" value="Remove"/> </form> Now, there's a component that I want to be editable. Basically, I want that third blah to be turned into a date. Here's what I wish I could do. <form action="removeThisData.html" method="post"> ... blah blah blah ...

问题 so I have a java class called User that contains a constructor like this: public class User extends Visitor { public User(String UName, String Ufname){ setName(UName); setFname(Ufname); } } And then the he problems occur in my other class called Admin: public class Admin extends User { //error "Implicit super constructor User() is undefined for default constructor. Must define an explicit constructor" //public Admin() { } //tried to add empty constructor but error stays there //} public void

问题 I'm trying to create a java method that returns the sum of two values x and y. Currently when I run the code, the output isn't returning anything. Is there any way I can get the value to return the sum WITHOUT modifying the "getSum(x,y);" in line 6 while using the return method??? public class ZawMethods2 { public static void main(String[] args) { int x = 7, y = 45; getSum(x,y); } public static int getSum(int x, int y){ int sum = x+y; return (sum); } } Thank you all in advance!!! I'm still in

问题 I'm trying to create a java method that returns the sum of two values x and y. Currently when I run the code, the output isn't returning anything. Is there any way I can get the value to return the sum WITHOUT modifying the "getSum(x,y);" in line 6 while using the return method??? public class ZawMethods2 { public static void main(String[] args) { int x = 7, y = 45; getSum(x,y); } public static int getSum(int x, int y){ int sum = x+y; return (sum); } } Thank you all in advance!!! I'm still in

问题 I have problem with List<T>.Reverse() and Reverse(this IEnumerable<TSource> source) . Look to the code: // Part 1 List<int> list = new List<int> { 1, 2, 3 }; foreach (int x in list) Console.Write(x); Console.WriteLine(); list.Reverse(); foreach (int x in list) Console.Write(x); Console.WriteLine(); list.Reverse(); // Part2 IList<int> ilist = list; foreach (int x in list) Console.Write(x); Console.WriteLine(); ilist.Reverse(); foreach (int x in ilist) Console.Write(x); Console.WriteLine();

问题 I have a parser method inside my component, when that method is working I want to create components (or even just elements) from values that is computed. Is it possible to creating component or html elements when method is working? 回答1: Is it possible to creating component or html elements when method is working? Its not possible in JavaScript using synchronous code . JavaScript is single-threaded and even browser rendering is blocked when your synchronous/long running code is executing, not

问题 I had a bug where I was relying on methods being equal to each other when using is . It turns out that's not the case: >>> class What(object): def meth(self): pass >>> What.meth is What.meth False >>> inst = What() >>> inst.meth is inst.meth False Why is that the case? It works for regular functions: >>> def func(): pass >>> func is func True 回答1: Method objects are created each time you access them . Functions act as descriptors, returning a method object when their .__get__ method is called