this

问题 Here's a sample of a simple Javascript class with a public and private method (fiddle: http://jsfiddle.net/gY4mh/). function Example() { function privateFunction() { // "this" is window when called. console.log(this); } this.publicFunction = function() { privateFunction(); } } ex = new Example; ex.publicFunction(); Calling the private function from the public one results in "this" being the window object. How should I ensure my private methods are called with the class context and not window?

问题 I get the recursive construct overflow invocation error at the four public tuna parts (parts=maybe a class or something else?). It worked on the tutorial but not for me and can't seem to see where public class tuna { private int hour; private int minute; private int second; public tuna() { this(0,0,0); //default } public tuna(int h){ this(h,0,0); //with hours input } public tuna(int h, int m){ this(h,m,0); //with hours and minutes } public tuna(int h, int m, int s){ this(h,m,s); //with hours,

问题 Background: I have a recursive function implemented by a Z-combinator as is shown here and here so it makes no use of arguments.callee since it will be deprecated in upcoming ES6 . Issue The main issue with the Z-combinator and all recursive anonymous functions I've seen so far is that they updates de this value to the inner function scope (the self-returned at the return clause), so the this that references the top level is lost, and I want to maintain it through all the inner functions. Is

问题 In a function, how to you assign this a new value? 回答1: You can't. 9.3.2 The this pointer [class.this] 1 In the body of a non-static (9.3) member function, the keyword this is a prvalue expression whose value is the address of the object for which the function is called. [...] (emphasis & link mine) You can modify the object this points to, which is *this . For example: struct X { int x; void foo() { this->x =3; } }; The method modifies the object itself, but something like this = new X is

问题 This question already has answers here : How can I merge properties of two JavaScript objects dynamically? (60 answers) Why can't I assign a new value to “this” in a prototype function? (4 answers) Closed 3 years ago . I'm trying to merge the props from values into this . The following throws an error. How can I do this? this = {...this, ...values} 回答1: You could extend this with Object.assign method: class Foo { constructor (props) { Object.assign(this, props); } } const foo = new Foo({ a: 1

问题 There is more than one stackoverflow question about how to find the min or max of an array of values in javascript. This is not that question. I want to know why passing .apply() strange things as the this argument still works. Despite a good blog post from Aaron Crane on how the Math object's API became what it is, there's still something left unanswered. Each of the following code snippets work. My question is, how? What exactly is happening with the assignment to this that makes each of

问题 I encountered a code where this() method in java takes three parameters two being integers and the third one is boolean value. what exactly does that mean ? Are there any other variants of this() method ? Hera is the actual code. public SegmentConstructor(int seqNum_, int length_) { this(seqNum_, length_, false); } Thank You.. 回答1: It means that there is another constructor in the current class that has that signature. public SegmentConstructor(int seqNum_, int length_) { this(seqNum_, length

问题 Please explain me that for what $this and -> stands for...lets take the example of following code... $this->convertNamesToCaptions($order, $formId) 回答1: $this refers to the current object Manual says: The pseudo-variable $this is available when a method is called from within an object context. $this is a reference to the calling object (usually the object to which the method belongs, but possibly another object, if the method is called statically from the context of a secondary object).

问题 What does 'this' keyword refer to when used in gloabl object? Let's say for instance we have: var SomeGlobalObject = { rendered: true, show: function() { /* I should use 'SomeGlobalObject.rendered' below, otherwise it won't work when called from event scope. But it works when called from timer scope!! How can this be? */ if(this.rendered) alert("hello"); } } Now if we call in an inline script in the HTML page: SomeGlobalObject.show(); window.setTimeout("Msg.show()", 1000); everything work ok.

问题 I just figured that I can use the this keyword in an interface . So, if this keyword represents current class object reference in a class , then what does it represent in an interface ? interface InterfaceOne { default void display() { this.defaultMethod(); System.out.println("InterfaceOne method displayed"); } default void defaultMethod() { System.out.println("defaultMethod of InterfaceOne called"); } } 回答1: Even in this case, the this keyword is used in the same context and meaning. One