modifier

问题 Does the Ruby rescue statement modifier work with require ? irb(main):001:0> require 'a' rescue nil LoadError: no such file to load -- a from (irb):1:in `require' from (irb):1 from :0 回答1: You can rescue from a LoadError you just need to use the begin/end style and not use the inline rescue : This works as you expect: begin require 'a' rescue LoadError => ex puts "Load error: #{ex.message}" end 来源： https://stackoverflow.com/questions/12750546/does-the-ruby-rescue-statement-work-with-require

问题 I'm self-answering this question because I've seen it asked all over the Internet, but with few helpful answers, and definitely no resolutions on Stack Overflow that I can find. Example Code Consider this code, which simply writes several lines of shell commands: ^0:: SetKeyDelay, 0, 0 myWindow = ahk_exe Notepad.exe ControlSend, , set c=".cshrc-andrew.cheong"`n, %myWindow% ControlSend, , set v=".vimrc-andrew.cheong"`n, %myWindow% ControlSend, , foreach d ( /userhome/andrew.cheong /home/$USER

问题 I'm self-answering this question because I've seen it asked all over the Internet, but with few helpful answers, and definitely no resolutions on Stack Overflow that I can find. Example Code Consider this code, which simply writes several lines of shell commands: ^0:: SetKeyDelay, 0, 0 myWindow = ahk_exe Notepad.exe ControlSend, , set c=".cshrc-andrew.cheong"`n, %myWindow% ControlSend, , set v=".vimrc-andrew.cheong"`n, %myWindow% ControlSend, , foreach d ( /userhome/andrew.cheong /home/$USER

问题 I have two classes in two different packages: package package1; public class Class1 { public void tryMePublic() { } protected void tryMeProtected() { } } package package2; import package1.Class1; public class Class2 extends Class1 { doNow() { Class1 c = new Class1(); c.tryMeProtected(); // ERROR: tryMeProtected() has protected access in Class1 tryMeProtected(); // No error } } I can understand why there is no error in calling tryMeProtected() since Class2 sees this method as it inherits from

问题 Whenever I look deeply enough into reflector I bump into extern methods with no source. I read the msdn documentation at http://msdn.microsoft.com/en-us/library/e59b22c5(v=vs.80).aspx. What I got from that article is that methods with the extern modifier have to be injected. I interpreted this to mean it works something like an abstract factory pattern. I also noticed that I've never seen a non-static extern method. Is static declaration a requirement (I could see how this would make sense)?

问题 The ObjectiveC.swift file from the standard library contains the following few lines of code around line 228: extension NSObject : Equatable, Hashable { /// ... open var hashValue: Int { return hash } } What does open var mean in this context, or what is the open keyword in general? 回答1: open is a new access level in Swift 3, introduced with the implementation of SE-0117 Allow distinguishing between public access and public overridability It is available with the Swift 3 snapshot from August

问题 When used like this: import static com.showboy.Myclass; public class Anotherclass{} what's the difference between import static com.showboy.Myclass and import com.showboy.Myclass ? 回答1: See Documentation The static import declaration is analogous to the normal import declaration. Where the normal import declaration imports classes from packages, allowing them to be used without package qualification, the static import declaration imports static members from classes, allowing them to be used

问题 Currently i can print out the type size and range of a;; primitive java data types except bollean using the following method. public class sizJ { public static void display(Class<?> type, int size, Number min, Number max) { System.out.printf("%-6s %-2s %-20s %s\n", type, size, min, max); } public static void main(String[] args) { System.out.printf("%s %-2s %-20s %s\n","type","size","min","max"); display(Byte.TYPE, Byte.SIZE, Byte.MIN_VALUE, Byte.MAX_VALUE); display(Character.TYPE, Character

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: Protected in Interfaces The following code snippet shows that an interface in Java can have only one modifier which is public . No other modifiers (private and protected) are allowed within an interface neither with fields nor with any methods. Obviously among modifiers, private has no meaning to use within an interface but protected should be allowed within an interface because it can be incorporated by it's

问题 This question already has answers here : Protected in Interfaces (16 answers) Closed 3 years ago . I have an interface and 2 classes that implement this interface. See the code below as example. addAchievedMilestone is a method that needs to be implemented in every class, but can only be executed by a class in the same package. Why can't the method addAchievedMilestone be protected? I want it to be protected so it can only be used by classes in the same package. (The method won't be extended