How to extend the constructor for the date object of the javasccript so that whenever a call is made to the constructor, I want to perform a particular action? Basically how to define wrappers for default javascript methods or objects like Date() so that I can perform some action and then invoke the original method? So basically if I have something like var a = new Date(); I want it to (say) alert the value of the date everything Date() is called and then execute the default date constructor.
How would I go about copying all the prototype functions AND the constructor from one object into another object, and then call them?
I know I can use this.example.call(this), but that's not an acceptable solution. I want to deploy this style over dozens, potentially hundreds of objects.
As I know,it's not well to extend Object.prototype derictly. In the Prototype(JS Framewoke),there is no extend Object.prototype. It only add some static method for Object class.I want to konw the reason.
I need to detect the "name" of the constructor of an object. For example, myArray.constructor === Array is true, but I want something where that === 'Array' is true. I've heard of Object.constructor.name, but it's not widely compatible. (preferably without involving regular expressions)?
Now, the code worked fine in both script. (i.e., no more error.) So far as I can tell, the only differences between the first and next version of Book.js are the comments and the whitespace. Am I missing something? Can the comments or whitespace somehow effect the logic with which this code has been executing? If I get an error like this again, is there an easier/better way to fix it than to essentially retype the code?
What happens if you do the following? - That is deep copy a jQuery selector.
[Code]...
I'm concerned whether the myObj.selector object will deep copy the whole of jQuery as part of the process. My initial tests did not show any obvious speed hit, but it is rather a basic test right now.
I have a requirement to override the constructor of a javascript class. I have to execute the current constructor code and then call a javascript method. Basically, I need to execute a javascript method whenever an object of that particular class is created in addition to whatever is being done now. I do not want to copy and paste the current constructor code and override the initcomponent method. I am looking for an alternative for that.
I need to create a constructor for a computer object. This object must have three properties: speed, and mem_live mem_dead. Then I need to create a new object using this constructor and then have its properties displayed on the screen.Look at what I'm up to so far:
function Computer(speed, mem_live, mem_dead) { this.speed = speed;
function show() { var s = '' ; for (var i = 0; i<arguments.length; s += ' '+arguments[i++]) ; typeof(window) != 'undefined' ? window.alert(s) : WScript.Echo(s) ; }
function f(){} show('delete(f):',delete(f)) ; // false
Sorry, bad title. Anyway, is there a way to pass the arguments to an object instantiated via a constructor using the arguments object and have it expanded, so to speak, so that it doesn't appear as a single argument? I'm sorry, this explanation is just atrocious, but I can't think of exactly how to word it. Maybe an example...
Take for instance Function.apply. It takes 1-2 arguments, the first being the object to use as the context, and the second being either an array or an instance of the arguments object which are to be the arguments for the function. I want to do something similar but I want to also basically use the new operator so that I get back an object.
Here's a snippet of some of my code, maybe this will help:
I'm sure this question has been asked many times before, but I can't seem to get the correct terms to find the answer in Google.I understand basic JavaScript inheritance. However, everything I've read makes the inheritance work something like this:
Code JavaScript: var ChildClass = new Function(); ChildClass.prototype = new ParentClass(); ChildClass.constructor = ChildClass;
That's fine, but what happens when ParentClass's constructor needs parameters?As an example, look at the following code:
Code JavaScript: function Furniture(color){ this.color = color;[code)....
How could I "copy" Furniture's constructor into the Chair object? Better yet, how could I copy Furniture's constructor and then add some functionality to it?
The problem is I keep getting an error along the lines of: TypeError: Result of expression 'house' [[object Object]] is not a constructor. It seemed to work when I wasn't passing the other objects as parameters in the constructor. I just created and assigned them later. As in:
I'd like to make a Degree object that inherits from the Number object and uses the Number constructor but adds a .rad() method that returns the value in radians.
If I do something like:
It generally works but I don't get Number's methods like toString and toPrecision.
I have a few String prototypes such as String.prototype.EscapeReg = function () { return this.replace(/[-[]{}()*+?.,\^$|#s]/g, "\$&"); }; // Escapes characters for use with a regular expressionI also have my own class/ library which is used like this var adg = new AndyG_ns.ADG_Utils(); adg.StartClock('AndyClock','dd mmm yy hh:nn'); // etc.What I would like to do is to only add the prototype to my library (not to the global namespace). The end result I'm looking for is to use code such as:
var adg = new AndyG_ns.ADG_Utils(); var myString = new adg.AString(); var parsed = myString.EscapeReg();
In addition, I want to be able to also use/create my special string sub-class within my library. I suppose I'm saying that I would like to extend or super-class the native String object.
I had read from books that the constructor property of object is inherited from its prototype. And the prototype can be changed dynamically. New property can be added to or deleted from object even it was created before the prototype change.
I have static object and I want remake it to a constructor with property 'length' which would be not enumerable in for loop... This is my object and how I generate it
Is there any way at all to create a new template object that inherits from the built in Date object so as to be able to add new methods to that child object without adding them to the built in Date object? I've tried everything I can think of and as far as I can tell it keeps referencing the Date function instead of the Date object and so doesn't work.
<script type="text/javascript"> var d=new Date() var arr=new Array("Jun 5",d,"Mar 16") for(i=0;i<arr.length;i++){ if(arr[i] != Date()) // is string or is not date object document.write(arr[i] + "<br>") } </script>
The goal is for selectedDay to be assigned the value of the system variable Mainpackage.subclass0.subclass1.firstDay and then incremented by two days. Mainpackage.subclass0.subclass1.firstDay needs to be unchanged.
Important system variable in red. To be 'manipulated and used' variable in green. Even with an intermediary, third, dummy variable it doesn't work:
Console log is:
It doesn't work in my webapp : All variables change at the same time.
I have a question about what the most certain method to obtain the correct UTC time in javascript is.On my forum, there is a countdown clock, that should show the same amount, wherever the user is located. I use UTC in javascript to get the current time, but I have trouble getting consistent results.I have tried two methods:Method 1:
Code: var d = new Date(); var localTime = d.getTime();
