syntax

问题 I have multiple cases in a switch that do the same thing, like so: (this is written in Java) case 1: aMethod(); break; case 2: aMethod(); break; case 3: aMethod(); break; case 4: anotherMethod(); break; Is there any way I can combine cases 1, 2 and 3 into one case, since they all call the same method? 回答1: case 1: case 2: case 3: aMethod(); break; case 4: anotherMethod(); break; This works because when it happens to be case 1 (for instance), it falls through to case 2 (no break statement),

问题 I'm working through the Stanford iPhone podcasts and have some basic questions. The first: why is there no easy string concatenation? (or am I just missing it?) I needed help with the NSLog below, and have no idea what it's currently doing (the %@ part). Do you just substitute those in wherever you need concatenation, and then comma separate the values at the end? NSString *path = @"~"; NSString *absolutePath = [path stringByExpandingTildeInPath]; NSLog(@"My home folder is at '%@'",

问题 With introduction of open keyword in Swift 3.0 (What is the 'open' keyword in Swift?). Note: Limited to extensions on NSObject derived classes or @objc attributed method/properties. Code wich declared and used public ( class ) methods/properties in extension across modules/frameworks broke, as public is no longer means 'overridable' outside of defining module. Example: public extension UIManagedDocument { public class func primaryDocumentName() -> String { return "Document" } public class

问题 I'm trying to re-purpose some Javascript code I found linked in an answer on SO. But I would like to understand its syntax better first. Its outline is: (function (root, ns, factory) { // some code } (window, 'detectZoom', function() { // some more code })); See accepted answer in this post for the reference to the full code. I understand how the end-result is achieved, but I don't quite know how the inner (...) block relates to the first, or what the comma separated list inside it tells the

问题 I have defined a Java function: static <T> List<T> createEmptyList() { return new ArrayList<T>(); } One way to call it is like so: List<Integer> myList = createEmptyList(); // Compiles Why can't I call it by explicitly passing the generic type argument? : Object myObject = createEmtpyList<Integer>(); // Doesn't compile. Why? I get the error Illegal start of expression from the compiler. 回答1: When the java compiler cannot infer the parameter type by itself for a static method, you can always

问题 Why can't I add a delegate to my interface? 回答1: You can use any of these: public delegate double CustomerDelegate(int test); public interface ITest { EventHandler<EventArgs> MyHandler{get;set;} CustomerDelegate HandlerWithCustomDelegate { get; set; } event EventHandler<EventArgs> MyEvent; } 回答2: A Delegate is just another type, so you don't gain anything by putting it inside the interface. You shouldn't need to create your own delegates. Most of the time you should just use EventHandler,

问题 What's the best way to chain methods in CoffeeScript? For example, if I have this JavaScript how could I write it in CoffeeScript? var req = $.get('foo.htm') .success(function( response ){ // do something // ... }) .error(function(){ // do something // ... }); 回答1: Using the latest CoffeeScript, the following: req = $.get 'foo.html' .success (response) -> do_something() .error (response) -> do_something() ...compiles to: var req; req = $.get('foo.html').success(function(response) { return do

问题 I keep getting syntax error if i use instructions like li or la. If i try a code without these instructions it works fine, but i need to use them. I tried different versions and i keep getting the same error (I have allowed pseudo instructions). I need to use it for a university project but i can't check if the code i wrote is ok since i can't run the code. Am i missing something? I don't know how to make it work properly, i'm new to assembly and pcspim, so i may be overlooking something

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 . I am using python 2.7.4 on a Linux machine. My guide is the book "Learn Python the hard way" and I am at 39th exercise and here's my code: # states and their abberavation states = [ 'Bihar' : 'BIH' 'Jharkhand' : 'JK' 'Bengal' : 'BEN' 'Tamilnadu' : 'TN' 'Haryana' : 'HY' 'Kerla' : 'KER' ] # states with their

问题 I have a simple example I've drawn up. I thought it was possible to combine if statements and for loops with minimal effort in Python. Given: sublists = [number1, number2, number3] for sublist in sublists: if sublist: print(sublist) I thought I could condense the for loop to: for sublist in sublists if sublist: but this results in invalid syntax. I'm not too particular on this example, I just want a method of one lining simple if statements with loops. 回答1: if you want to filter out all the