methods

问题 So, a method that alters its object is a mutator . A method that does not alter its object but returns a value (or reference to a value) is a getter . Is there a widely used name for a method that does not alter its object, does not return a value, but potentially alters objects passed to it as arguments. That is, a method that would only every be called for its side-effects on the arguments. These methods are quite common if you are keen on the Strategy design pattern. 回答1: I call these

问题 I'm trying to use Spring Security Annotations for security instead of defining the rules in XML. It seems to work, but when I run into an access denied error I get a HTTP status code of 500 returned. I do not see any exceptions in my tomcat log files. And when the execution hits my AuthenticationEntryPoint, the response is committed. If I revert to having the rules in XML and get an access denied error, I get a HTTP status code of 401 returned. The method is annotated with @PreAuthorize @GET

问题 So i have been looking into JNI calls so i can interact with some pre written C++ programs, i dont know any C++ but am trying to learn some basics. I have just been trying to do a simple call to a method outside my JNI method but always get the following error: error c3861 'myMethod': identifier not found #include <stdio.h> #include <string.h> #include "StringFuncs.h" JNIEXPORT jstring JNICALL Java_StringFuncs_changeWord(JNIEnv *env, jobject obj, jstring inStr, jint inLen) { const char

问题 I am trying to convert an object literal into an array of arrays by using a function. Using the two sample objects I have, the end result I'm looking for would be: [ ["ugh","grr"] , ["foo", "bar"] , ["blah" , 138] ] from obj1 [ "shambala","walawala"] , ["foofighter","Barstool"] , ["blahblah",1382342453] ] from obj2 var obj1 = { ugh: "grr", foo: "Bar", blah: 138 }; var obj2 = { shambala: "walawala", foofighter: "Barstool", blahblah: 1382342453 }; var piece1 = Object.keys(obj1); var piece2 =

问题 Is it possible (via reflection?) to iterate all fields of an object calling a method on each one. I have a class like so: public class Overlay { public Control control1; public Control control2; } I'd like a method that goes something like this: public void DrawAll() { Controls[] controls = "All instances of Control" foreach (Control control in Controls) { control.Draw() } } Can this be done? I've been able to get all the metadata on the Control class but this relates only to the type not the

问题 I found what looks like an elegant solution to iterating over enums here: How to enumerate an enum with String type? Next, I'm having trouble figuring out how to call this method. At face value, it doesn't look like it takes an argument, but when I try to call Card.createDeck() I get a compiler error telling me "error: missing argument for parameter #1 in call". Please let me know what I'm doing wrong here? What am I supposed to pass to this method? struct Card { var rank: Rank var suit: Suit

问题 In MATLAB, it is possible to define code suggestions and completions as explained in the documentation page titled "Customize Code Suggestions and Completions". The snippets given therein, e.g. { "_schemaVersion": "1.0.0", "anotherFunc": { "inputs": [ {"name":"input1", "kind":"required", "type":["numeric"]}, {"name":"input2", "kind":"required", "type":["numeric"]} ] } } show how we can control the predictions of functions found (presumably) in separate files in the same folder as

问题 I am trying to understand the recursion call in the below code snippet. static long fib(int n) { return n <= 1 ? n : fib(n-1) + fib(n-2); } Which function call does get called first? How does the equation work after the calls? Do both of these get called once and then equation applied or first one called and then the 2nd one? Maybe a very simple question! 回答1: Java and C&sharp; Sub-expressions are evaluated in left-to-right order. fib(n-1) is evaluated before fib(n-2) . See What are the rules

问题 I'm using Delphi Pro 6. Right now, the only way to know if a class is missing a base class abstract method is to wait for the IDE to emit a "constructing instance of {derived class} containing abstract method {base class.abstract method name}" warning or to wait for a runtime Abstract Error method when an attempt to call the missing method is made. The former isn't sufficient since it only finds warnings for those derived classes actually constructed in the current project. The latter is just

问题 I'm in the middle of creating a button that uses core data to save a name, xCoordinate, and yCoordinate of a point annotation. I can successfully persist the name, but I keep getting this error when I try to save a coordinate. I've logged the correct data, I just can't seem to save it. When I try to setValue for the newPOI, I get an error that reads: Sending 'float' to parameter of incompatible type 'id'. In the data model, the attribute is set to float. self.latitude and self.longitude are