closures

问题 Let us consider the workable code: var storage = {}; (function() { function internalMethod1() { ...; return; } function internalMethod2() { ...; return; } storage.storedMethod = internalMethod1; })(); storage.storedMethod(); Is there any way to call internalMethod2 , if it is not called in internalMethod1 ? In other words, can I access an anonymous closure from outside, if I have access only to one of its functions? 回答1: can I access an anonymous closure from outside? No. Scopes are private

问题 Let us consider the workable code: var storage = {}; (function() { function internalMethod1() { ...; return; } function internalMethod2() { ...; return; } storage.storedMethod = internalMethod1; })(); storage.storedMethod(); Is there any way to call internalMethod2 , if it is not called in internalMethod1 ? In other words, can I access an anonymous closure from outside, if I have access only to one of its functions? 回答1: can I access an anonymous closure from outside? No. Scopes are private

问题 var funcs = []; // let's create 3 functions for (var i = 0; i < 3; i++) { // and store them in funcs funcs[i] = function() { // each should log its value. console.log("My value: " + i); }; } for (var j = 0; j < 3; j++) { // and now let's run each one to see funcs[j](); } It outputs this: My value: 3 My value: 3 My value: 3 Whereas I'd like it to output: My value: 0 My value: 1 My value: 2 The same problem occurs when the delay in running the function is caused by using event listeners: var

问题 I'm using Django and Google's Closure javascript library, and I want to do some form processing via AJAX. Currently, I have a button on the page that says "Add score." When you click it, it fires off a goog.net.Xhrio request to load another URL with a form on it and display the contents in a little pop up box, via a call to loadForm() . loadForm = function(formId) { var form = goog.dom.getElement(formId); goog.style.setElementShown(goog.dom.getElement('popup-box'), true); goog.net.XhrIo.send

问题 Let's take this object: var person = { _name: "John", name: function() {return _name} } In GUI, myTextBox.value = person.name() will return "John" But myTextBox.value = person.name will return function() {return _name} How can I force both syntax to return "John" ? Could I use a closure (question I asked previously) somehow here? 回答1: You can't! You can't override javascript operators or keywords. you really can't have one operator\keyword that does two different things in the same context!

问题 This question already has answers here : Using an arbitrarily defined method of an anonymous interface (4 answers) Closed 5 years ago . I can imagine some very creative code in Java: Object thing = new Object() { public void speak() { System.out.println("Hi!"); } }; thing.speak(); Or even, to get the full closure effect, define a Function interface ... you get the idea? Why doesn't this code work? 回答1: i believe you can do it like this :- new Object() { public void speak() { System.out

问题 I wanted to have a static closure variable in my class, so that people can change the behavior of a specific part of the code. However, I can't seem to be able to initialize it anywhere. First I tried this: public static $logger = function($sql) { print_r($sql); }; But apparently PHP can't handle that. Ok, so I made a static init method: public static $logger; static function init() { /* if (!Base::logger) */ Base::logger = function($sql) { print_r($sql); }; } And call it at the end of the

问题 I'm trying to write a Rusty wrapper for a piece of C API. There is one C construct I struggle with: typedef bool (*listener_t) (int, int); bool do_it(int x1, int y1, int x2, int y2, listener_t listener) The function does its job for a range of numbers unless the listener returns false. In that case it aborts computation. I want to have a Rust wrapper like this: fn do_with_callback<F>(start: (i32, i32), end: (i32, i32), callback: F) where F: Fn(i32, i32) -> bool rust-bindgen created this for

问题 I'm trying to write a Rusty wrapper for a piece of C API. There is one C construct I struggle with: typedef bool (*listener_t) (int, int); bool do_it(int x1, int y1, int x2, int y2, listener_t listener) The function does its job for a range of numbers unless the listener returns false. In that case it aborts computation. I want to have a Rust wrapper like this: fn do_with_callback<F>(start: (i32, i32), end: (i32, i32), callback: F) where F: Fn(i32, i32) -> bool rust-bindgen created this for

问题 I'm trying to use JQuery .get() method and a javascript for loop to process some data from an external file. I've read about closures and return values from callbacks on stackoverflow for a couple hours, and i'm still confused why this isn't working. Are the variables headers and countryData not global in scope with respect to the inner callback function? They are being assigned values as intended within the callback function, but then how do i access them once that is complete? And possibly