scope

问题 I am writing a library in Java. I've divided its implementation into Java packages to help manage the complexity. Only one package contains classes that are visible to clients of the library. However, because only public methods are visible outside of the package for use by other packages of the library, I find myself forced to do one of the following: (1) Only put interfaces and factory methods in the externally-visible package, putting implementations of those interfaces in a separate

问题 So here is a sample code : import java.util.Scanner; public class Test { public static void main(String[] args) { System.out.println("Please type in a number"); Scanner in = new Scanner(System.in); switch (in.nextInt()){ case 1: save(in); break; case 2: System.out.println(value); break; default: System.out.println("Default case"); break; } in.close(); } public static String save(Scanner in){ System.out.println("Type in a word"); String value = in.next(); return value; } } In this particular

问题 I realize that when you submit the form in a jsp, in the mapped servlet you can get the desired data, set it in the proper scope(say request) and forward it to jsp like this: request.setAttribute("myList", myList); // Store list in request scope. request.getRequestDispatcher("/index.jsp").forward(request, response); However am wondering for pages which doesn't have a form or in other words we want to display data as soon as page loads, how can we efficiently load the data without using

问题 Could anyone explain why I can't print external: bar in the following example? As far as I know, the imported function externalFunction should be added to the global scope, and when invoked, should have the same scope than localFunction , isn't it? entry.js import { f as externalFunction } from './myfunction.js' function localFunction() { console.log('local: ' + foo) // 'local: foo' console.log('local: ' + bar) // 'local: bar' } foo = 'foo' var bar = 'bar' localFunction() externalFunction()

问题 Could anyone explain why I can't print external: bar in the following example? As far as I know, the imported function externalFunction should be added to the global scope, and when invoked, should have the same scope than localFunction , isn't it? entry.js import { f as externalFunction } from './myfunction.js' function localFunction() { console.log('local: ' + foo) // 'local: foo' console.log('local: ' + bar) // 'local: bar' } foo = 'foo' var bar = 'bar' localFunction() externalFunction()

问题 This question already has answers here : Short description of the scoping rules? (8 answers) Closed 5 years ago . From python reference manual: A scope defines the visibility of a name within a block. If a local variable is defined in a block, its scope includes that block. and When a name is used in a code block, it is resolved using the nearest enclosing scope. So it is not obviously from this quotes what scope does mean. Is it true that scope is a collection of bindings name-->value ? And

问题 This question already has answers here : Short description of the scoping rules? (8 answers) Closed 5 years ago . From python reference manual: A scope defines the visibility of a name within a block. If a local variable is defined in a block, its scope includes that block. and When a name is used in a code block, it is resolved using the nearest enclosing scope. So it is not obviously from this quotes what scope does mean. Is it true that scope is a collection of bindings name-->value ? And

问题 Here's a very simplified version of my Activity : public class Search extends Activity { //I need to access this. public SearchResultsAdapter objAdapter; public boolean onOptionsItemSelected(MenuItem itmMenuitem) { if (itmMenuitem.getItemId() == R.id.group) { final CharSequence[] items = {"Red", "Green", "Blue"}; AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setTitle(itmMenuitem.getTitle()); builder.setSingleChoiceItems(lstChoices), 0, new DialogInterface

问题 For example, given a basic controller such as: class PostsController < ApplicationController def index @post = Post.all end The instance variable @post is available in the view posts/index.html.erb but not the partial posts/_index.html.erb My primary questions are: Why is this? and How can I define a method for a partial in a controller to for example, pass an instance variable? On a more specific note: I ask this because the way I am rendering data in a separate, primary view welcome/index

问题 There is a global variable called numbers. Function one calculates a random number and stores it in mynumber variable. var mynumber; function one (){ var mynumber = Math.floor(Math.random() * 6) + 1; } I need to use it in a separate function as belows. But an error says undefined - that means the value from function one is not updated. function two (){ alert(mynumber); } How to overcome this problem. Is there a way to update the mynumber global variable. 回答1: If you declare a variable with