oop

问题 Right, so I'm trying to create a Contacts application using Python OOP. I'm fairly new to OOP and still trying to get my head around the concepts. I understand that a Class is a blueprint for all objects. I like to think of a Class as an entity and each Object is a record of that entity. I am from a Database background so that's why I interpret it like this, feel free to correct me. Anyways, in the Contacts app I'm making I've created the Class Contacts as outlined below: class Contacts():

问题 When defining a record class, how do I target the attributes to the parameter, field or property? For instance, I would like to use JsonIgnore but this doesn't compile as it has an attribute usage restriction to the field or property: record Person(string FirstName, string LastName, [JsonIgnore] int Age); 回答1: To target the various parts of the expanded class, use the appropriate attribute target. For instance: // Target the property, use `property` record Person(string FirstName, string

问题 When defining a record class, how do I target the attributes to the parameter, field or property? For instance, I would like to use JsonIgnore but this doesn't compile as it has an attribute usage restriction to the field or property: record Person(string FirstName, string LastName, [JsonIgnore] int Age); 回答1: To target the various parts of the expanded class, use the appropriate attribute target. For instance: // Target the property, use `property` record Person(string FirstName, string

问题 When defining a record class, how do I target the attributes to the parameter, field or property? For instance, I would like to use JsonIgnore but this doesn't compile as it has an attribute usage restriction to the field or property: record Person(string FirstName, string LastName, [JsonIgnore] int Age); 回答1: To target the various parts of the expanded class, use the appropriate attribute target. For instance: // Target the property, use `property` record Person(string FirstName, string

问题 This question already has an answer here : How to get if a key is pressed pygame [duplicate] (1 answer) Closed 20 days ago . I have created a Frogger Game Prototype and I'm wanting to not allow two keys to be pressed at the same time for movement. currently in my event function I have the following: for event in pygame.event.get(): # check for closing window if event.type == pygame.QUIT: if self.playing: self.playing = False self.running = False if event.type == pygame.KEYDOWN: if event.key =

问题 This question already has an answer here : How to get if a key is pressed pygame [duplicate] (1 answer) Closed 20 days ago . I have created a Frogger Game Prototype and I'm wanting to not allow two keys to be pressed at the same time for movement. currently in my event function I have the following: for event in pygame.event.get(): # check for closing window if event.type == pygame.QUIT: if self.playing: self.playing = False self.running = False if event.type == pygame.KEYDOWN: if event.key =

问题 Suppose I had the following class: class MyClass { public function Talk() { $Say = "Something"; return $Say; } } I then started an instance of the class: $Inst = new MyClass(); How can I now call $Say outside MyClass hence, for example, echo it on the document? For example, having something like: $Said = "He" . $Say 回答1: I strongly recommend you read through http://php.net/manual/en/language.oop5.php . It will teach you the fundamentals of OOP in PHP. In your example, $Say is just another

问题 Suppose I had the following class: class MyClass { public function Talk() { $Say = "Something"; return $Say; } } I then started an instance of the class: $Inst = new MyClass(); How can I now call $Say outside MyClass hence, for example, echo it on the document? For example, having something like: $Said = "He" . $Say 回答1: I strongly recommend you read through http://php.net/manual/en/language.oop5.php . It will teach you the fundamentals of OOP in PHP. In your example, $Say is just another

问题 Assume I have three classes like so. abstract class A { abstract protected function doSomething($object): array; } class B extends A { protected function doSomething(SomeObject $object): array { // something } } class C extends A { protected function doSomething(OtherObject $object): array { // something } } According to principles of inheritance as PHP does it, the structure described above is not legal PHP code, as the method definitions are not compatible with the base class. I can, of

问题 was the idea of nested functions considered to be useless during the time of developing older c++ standard, because its usage is basically covered by another concept like object-oriented programming; or it wasn't implemented just as a matter of simplification? 回答1: Nested functions - to be useful - need the stack frame of the containing function as context. Look at this: class Foo() { void Tripulate() { int i=0; void Dip() { // ... } int x = 12; for(i=1; i<=3; ++i) { int z= 33; Dip(); // ...