object

问题 I don't understand in JavaScript when to use the word "prototype" vs. using simple "dot" notation without the word "prototype". Can someone look at these code blocks and help me understand when you'd want to use one over the other? with "prototype": function employee(name,jobtitle) { this.name=name; this.jobtitle=jobtitle; } var fred=new employee("Fred Flintstone","Caveman"); employee.prototype.salary=null; fred.salary=20000; console.log(fred.salary); without "prototype": function employee

问题 I'm reading Effective C# and there is a comment about Object.GetHashCode() that I didn't understand: Object.GetHashCode() uses an internal field in the System.Object class to generate the hash value. Each object created is assigned a unique object key, stored as an integer, when it is created. These keys start at 1 and increment every time a new object of any type gets created. The object identity field is set in the System.Object constructor and cannot be modified later. Object.GetHashCode()

问题 I am looking to use my screen real estate to look at several simple lists side by side. I'm not trying to combine them, a la cbind , but I wouldn't mind if a new intermediate structure were created. Realize, of course, that a list may have many different types of objects, though I will almost guarantee that my lists have the same structures; feel free to insert "NA" or "NULL" if necessary to make things work (or I can figure out how to wrangle that). Here are three example lists that I would

问题 class Foo(object): pass foo = Foo() def bar(self): print 'bar' Foo.bar = bar foo.bar() #bar Coming from JavaScript, if a "class" prototype was augmented with a certain attribute. It is known that all instances of that "class" would have that attribute in its prototype chain, hence no modifications has to be done on any of its instances or "sub-classes". In that sense, how can a Class-based language like Python achieve Monkey patching? 回答1: The real question is, how can it not? In Python,

问题 class Foo(object): pass foo = Foo() def bar(self): print 'bar' Foo.bar = bar foo.bar() #bar Coming from JavaScript, if a "class" prototype was augmented with a certain attribute. It is known that all instances of that "class" would have that attribute in its prototype chain, hence no modifications has to be done on any of its instances or "sub-classes". In that sense, how can a Class-based language like Python achieve Monkey patching? 回答1: The real question is, how can it not? In Python,

问题 class Foo(object): pass foo = Foo() def bar(self): print 'bar' Foo.bar = bar foo.bar() #bar Coming from JavaScript, if a "class" prototype was augmented with a certain attribute. It is known that all instances of that "class" would have that attribute in its prototype chain, hence no modifications has to be done on any of its instances or "sub-classes". In that sense, how can a Class-based language like Python achieve Monkey patching? 回答1: The real question is, how can it not? In Python,

问题 I'm attempting to create an array of objects in php and was curious how I would go about that. Any help would be great, thanks! Here is the class that will be contained in the array <?php class hoteldetails { private $hotelinfo; private $price; public function sethotelinfo($hotelinfo){ $this->hotelinfo=$hotelinfo; } public function setprice($price){ $this->price=$price; } public function gethotelinfo(){ return $hotelinfo; } public function getprice(){ return $price; } } And here is what I am

问题 Is there a way to retrieve the time an object was created at? 回答1: Not generally but you can do it for objects you create yourself via R> df <- data.frame(a=sample(LETTERS[1:5],10,TRUE),b=runif(10)) R> attr(df, "createdAt") <- Sys.time() R> df a b 1 B 0.8437021 2 D 0.8683446 3 B 0.5194791 4 B 0.0480405 5 B 0.5604978 6 C 0.1938154 7 A 0.1451077 8 D 0.1785405 9 C 0.3937795 10 B 0.2874135 R> str(df) 'data.frame': 10 obs. of 2 variables: $ a: Factor w/ 4 levels "A","B","C","D": 2 4 2 2 2 3 1 4 3

问题 Ok I'm stumped on this one. I need to iterate through these so I can make a listing by the category so something like Business Books Book 1 Book 2 Book 3 Cooking Books etc.. But couldn't figure out how to iterate through the nested objects. With or without jquery is fine window.books = { "Business Books": [ { Title: "Finance 101", Description: "Info for Finance 101 book goes here." }, { Title: "Economics 123", Description: "Info for Economics 123 book goes here." }, { Title: "Statistics for

问题 Ok I'm stumped on this one. I need to iterate through these so I can make a listing by the category so something like Business Books Book 1 Book 2 Book 3 Cooking Books etc.. But couldn't figure out how to iterate through the nested objects. With or without jquery is fine window.books = { "Business Books": [ { Title: "Finance 101", Description: "Info for Finance 101 book goes here." }, { Title: "Economics 123", Description: "Info for Economics 123 book goes here." }, { Title: "Statistics for