methods

问题 Why is the 'self'-call to a non-satic method in this example working? class A{ protected function aNonStaticMethod(){ return __class__; } public function aEcho(){ echo self::aNonStaticMethod(); } } Thanks for explanation. 回答1: Calling non-static method statically Theoretically it should not work, but as this comment says: There was no static keyword in php4 but php4 did allow for static calls. To maintain backwards compatibility this was left in when the static keyword was added in php5. This

问题 I was following a tutorial today that had me scratching my head for an hour. Consider: public class MyClass { public int getTotal() { amount = 100; return amount; } } and an excerpt from a JSP: <p>Total: ${objectOfTypeMyClass.total}</p> //object instantiated elsewhere Nowhere in the code was an instance variable named " total " ever declared or used. The only reference to the word "total" in the whole project (other than in the JSP) was the method getTotal() . So after some desperate last

问题 This question already has answers here : How does polymorphism work in Python? (3 answers) Python function overloading (14 answers) Closed 5 years ago . I'm learning Python (3.x) from a Java background. I have a python program where I create a personObject and add it to a list. p = Person("John") list.addPerson(p) But for flexibility I also want to be able to declare it directly in the addPerson method, like so: list.addPerson("John") The addPerson method will be able to differentiate whether

问题 I have 2 flash games (written in as3). Both the highscore value being hacked. The normal range of each game score is not more than 5000 (normal users, will only get 2000 - 3000 points). My current method of anti-hacking is: After finish the game, flash will use post parameters send: username=mike&score=2000&hash=md5(secret . username . score). In php page, I did the check, if the hash != md5(secret . username . score), it will return error, and WONT insert data into database. I believe this

问题 How to write the following code correctly? public String toString(int[] position, int xOffset, int yOffset) { String postn = String.format("[%d,%d]", position[0], position[1]); String movm = String.format("[%d,%d]", xOffset, yOffset); return (postn, movm); } Following error came up movm cannot be returned. 回答1: When using Java 8 you could make use of the Pair class. private static Pair<String, String> foo (/* some params */) { final String val1 = ""; // some calculation final String val2 = ""

问题 Do interfaces in PHP have properties, or do they only have methods? 回答1: It depends what you mean by "properties". If you mean actual fields, then no, they don't. If you're referring to properties such as those in C#, then yes they can (since the property accessors are strictly syntactic sugar for accessor methods anyway). The same goes for events (though of course, in each case, no implementation is specified for the get / set or add / remove accessors). Update : Since PHP does not have

问题 I am trying to do a chaining method for the following two methods. After running this code, I kept getting the following output: #<SimpleMath:0x007fc85898ab70>% My question is: what is the proper way of chaining methods in Ruby ? Here is my codes: class SimpleMath def add(a,b=0) a + b return self end def subtract(a,b=0) a - b return self end end newNumber = SimpleMath.new() print newNumber.add(2,3).add(2) 回答1: Are you trying to do something like this? class SimpleMath def initialize @result =

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . decided to recently learn a little bit of java and I've been stumped at the first hurdle. Here is my extremely basic code: import java.util.Scanner; class helloWorld{ public static void main(String[] args){ Scanner user_input = new Scanner(System.in); int a = 50; String first_name; String last_name; public

问题 I have a "private static" nested class in Java. What is the significance of access modifiers for fields and methods inside this class? I've tried both public and private with no effect on my application. public class MyList<T>{ private static class Node{ // List node private Object item; private Node next; private Node prev; private Node(Node next){ this.next = next; } private static Node doStuff(){} } } 回答1: Two kinds of nested classes: 1. Static (nested class) and 2. Non-static (also called

问题 Previously, I asked about a clever way to execute a method on a given condition "Ruby a clever way to execute a function on a condition." The solutions and response time was great, though, upon implementation, having a hash of lambdas gets ugly quite quickly. So I started experimenting. The following code works: def a() puts "hello world" end some_hash = { 0 => a() } some_hash[0] But if I wrap this in a class it stops working: class A @a = { 0 => a()} def a() puts "hello world" end def b() @a