scope

问题 I am having trouble understanding how to work with objects. The specific code: class first{ class second{ public function widgets(){ $a_variable = $a_value; } #1 } $second = new second; #2 } #3 $first = new first; If I initialize $a_variable as $a_variable it is only available inside the function, correct? If I initialize $a_varialbe as $this->a_variable it is only available inside class second, correct? Can I initialize $a_variable as $first->second->a_variable ? If so, How would I call it

问题 I have the following nested function: int main() { int a, b, c; a = 10; int foo() { int a, b, c; //some more code here } // some more code here } Now, I need to assign the variable a that belongs to foo() , with the value of the variable a that belongs to main() . Basically, something like foo.a = main.a is what I'm looking for. Is there any way of doing this kind of assignment? I read through scope rules here and here , but didn't find anything I could use in this situation. I know that

问题 I have this line of code. class ButtonPanel extends JPanel implements ActionListener { public ButtonPanel() { yellowButton = new JButton("Yellow"); and It works, I thought Java needs to know the type of yellowButton before creating an instance of a jButton like this? JButton yellowButton = new JButton("Yellow"); can somebody explain how this works? 回答1: If it really does work, then that means yellowButton is probably a class field that you didn't notice. Check the class again. What you

问题 I am trying to hook some jQuery to my nav to fade in and out the page wrapper when someone click on a main nav link. The code itself is working fine, but just have 2 issues: There is a flash in beggining like it loads everything, removes it, then fades it in (not sure if this is CSS related). The links are broken. For example: when you click "contact" instead of going to www.domain.com/contact it goes to www.domain.com/undefiend Any help would be great. Thanks!! JS $(document).ready(function(

问题 I have been working with the module pattern in JavaScript and have a question about scope and square bracket notation (SBN). Please consider the following simple example. (function (module) { function myMethod(text) { console.log(text); } module.init = function (name) { // here I want to do something like // eval(name)("hello"); // using SBN, e.g. ..[name].call(this, "hello"); }; })(window.Module = window.Module || {}); Module.init("myMethod"); From within the init function is it possible to

问题 In my Angular project, I am using a particular value that in my controller is called something like: $scope.feature1.items.thisItem There's a particular <div> in my view that uses thisItem many times and it's quite messy to be referring to it as {{feature1.items.thisItem}} for example: <div id="{{feature1.items.thisItem}}header> <h1> You've reached the section about {{feature1.items.thisItem}} </h1> </div> Is there any way to rename this variable in the view? I would like to simply call it

问题 Before I have the audacity to file a bug report, I thought I'd check my assumptions among wiser Pythonistas here. I encountered a baffling case today, so I whittled it down to a toy example, shown below: #!/usr/bin/env python # -*- coding: UTF-8 -*- """ A little script to demonstrate that a function won't re-initialize its list parameters between calls, but instead allows them to retain state. """ def bleedscope(a=[], b=[]): """ On each call, unless explicitly passed, both `a` and `b` should

问题 Is there any way to change a variable while out of scope? I know in general, you cannot, but I'm wondering if there are any tricks or overrides. For example, is there any way to make the following work: function blah(){ var a = 1 } a = 2; alert(blah()); EDIT (for clarification): The hypothetical scenario would be modifying a variable that is used in a setInterval function which is also out of scope and in an un-editable previous javascript file. It's a pretty wacky scenario, but it's the one

问题 When I get a spring bean (via getBean()), is there any way to verify from java code that the bean has been defined with scope=prototype ? Spring config: <bean class="foo.Bar" scope="prototype" /> Java:sc MyBean bean = springApplicationContext.getBean("MyBean"); I could just instantiate it twice and compare the objects, but I'd like to avoid unnecessary object creation. Something like the opposite of this answer would do the trick: https://stackoverflow.com/a/9125610/156477 回答1: You have a API

问题 In the code below there is callback function used with forEach loop going over returned results. Is variable 'error' inside forEach loop and 'error' in callback same variables ? session.getAll(options, function (error, varbinds) { varbinds.forEach(function (vb) { if (error) console.log('getALL Fail '); else console.log(vb.value); }); }); 回答1: Yes, it is the same variable. I'm not sure how much you know. So, I'm going to explain in detail. Scoping in JavaScript is at the function level*. Think