switch-statement

问题 I've used the switch statement the following way: switch (ch){ case 'P' || 'p': goto balance; break; case 'r' || 'R': goto menu; break; default: cout<<"\t\tInvalid Choice!!"<<endl; system ("\t\tpause"); system ("cls"); goto menu; break; } But it seems there's something wrong with the following syntax: case 'r' || 'R' Compiler complains about "duplicate case value". What's wrong with my code? 回答1: Change it to case 'P': case 'p': goto balance; break; Using goto is usually not a good idea. In

问题 I'm not sure which one is better. I need to parse each character of an input string and get a replacing string for the character. For some objects all alphanumeric characters are allowed so using switch/case will cause a lot of code and reduce readability and maintainability but I can use a static method. Using a HashTable also requires a lot of code Using the static method: private static string EncodeChar(char c) { var symbols = string.Empty; switch (c) { case '0': symbols = "Test"; break;

问题 I am doing a POC on Java 7 new features. I have code to use String in switch statement and it works. I want to make it work in case insensitive also. Is there a way to check out with ignoreCase on String? package com.java.j7; public class Test { final private String _NEW ="NEW"; final private String _PENDING = "PENDING"; final private String _CLOSED = "CLOSED"; final private String _REJECTED ="REJECTED"; public static void main(String... strings){ Test j = new Test(); j.processItem("new"); j

问题 <? switch ($var): ?> <? case 1: ?> It's 1! <? break ?> <? endswitch ?> I want to do something like that, in other words use the switch statement in PHP templates. This is possible with the if statement. The above code generates Parse error: syntax error, unexpected T_INLINE_HTML, expecting T_ENDSWITCH or T_CASE or T_DEFAULT in PHP 5.3. The PHP docs suggests that this should be possible. Can someone confirm that this doesn't work, or rather, tell me what I'm doing wrong? Thanks. 回答1: I read in

问题 <? switch ($var): ?> <? case 1: ?> It's 1! <? break ?> <? endswitch ?> I want to do something like that, in other words use the switch statement in PHP templates. This is possible with the if statement. The above code generates Parse error: syntax error, unexpected T_INLINE_HTML, expecting T_ENDSWITCH or T_CASE or T_DEFAULT in PHP 5.3. The PHP docs suggests that this should be possible. Can someone confirm that this doesn't work, or rather, tell me what I'm doing wrong? Thanks. 回答1: I read in

问题 I understood why Duff's device is faster than normal loop code which can be unrolled but is not optimized. But I can't understand how the code can be compiled yet. I guess it's a trick about the switch syntax. But not anymore. How can do while sentence exist in switch sentence? Very weird. Is there anyone who can explain this? Edit: Another question. Why did duff use 8? It could be 16, 65536 or whatever. Because of code size? Is there another reason? For example, cache or pipelining benefits.

问题 I understood why Duff's device is faster than normal loop code which can be unrolled but is not optimized. But I can't understand how the code can be compiled yet. I guess it's a trick about the switch syntax. But not anymore. How can do while sentence exist in switch sentence? Very weird. Is there anyone who can explain this? Edit: Another question. Why did duff use 8? It could be 16, 65536 or whatever. Because of code size? Is there another reason? For example, cache or pipelining benefits.

问题 I'm fairly new to Xamarin.Forms and tried googling my question. I have a ListView of SwitchCells, the ItemsSource is a Collection of a simple Data-Class. Now when I change the Switch's state in the SwitchCell I want to have a Method being called...that should not be the problem, but I can't figure out how I know wich SwitchCell, or in other words wich Instance of the DataClass, wich Item was switched. I expect it to be something like the code I commented, but am really not sure...also I think

问题 I have a game in Swift where each of my levels is a separate class inherited from the base GameScene class (it's a lot easier this way for what I'm doing, don't judge me). I also have a menu which has a button for each level. This is how the buttons loads the level: override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { if let t = touches.first { let node = atPoint(t.location(in: self)) if let name = node.name { let newScene: GameScene! switch Int(name)! { case 1:

问题 I have a game in Swift where each of my levels is a separate class inherited from the base GameScene class (it's a lot easier this way for what I'm doing, don't judge me). I also have a menu which has a button for each level. This is how the buttons loads the level: override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { if let t = touches.first { let node = atPoint(t.location(in: self)) if let name = node.name { let newScene: GameScene! switch Int(name)! { case 1: