Converting a variable from one type to another

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0
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2answers
234 views

Optimization ended up in casting an object at each method call

I've been doing some optimization for the following piece of code : public void DrawLine(int x1, int y1, int x2, int y2, int color) { _bitmap.DrawLineBresenham(x1, y1, x2, y2, color); } After ...
1
vote
1answer
84 views

Ignoring the generic part of a type while an object is being passed

I have a message class that holds the name of a destination, and a generic variable acting as the message payload public class Message<T> { public string Destination public T Payload ...
2
votes
2answers
180 views

Having an inherited function return the derived type instead of the base type

I am writing two classes in C#: A Matrix class that represents a general Matrix with n-by-m dimensions A SquareMatrix class that inherits from Matrix and has the constraint of being n-by-n The ...
1
vote
3answers
70 views

Property-level value transformation for indirect object casting

Does any programming language exist to support the explicit, property-level object copy? For example, assume this code: public class Student { public string Name { get; set; } public ...
1
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3answers
190 views

Make Return Type an Interface - Problem with Initialization

I would like to make the return type of my method an interface rather than a class for similar reasons stated in c# List or IList, however I am having trouble figuring out how to initialize the ...
1
vote
2answers
131 views

A vector of pointers to different derived classes of the same base class

I am writing a game in C++ which has different enemy types. I have defined a base Enemy class and I also have derived classes enemy1, enemy2 etc. Now for updating these enemies in each iteration of ...
0
votes
2answers
608 views

Why doesn't Ruby have implicit conversion of Fixnum into String?

Ruby normally makes things easy. However, it doesn't allow implicitely converting a number to a string: 2.0.0p247 :010 > "a"+1 TypeError: no implicit conversion of Fixnum into String Why is this ...
6
votes
6answers
603 views

How to avoid downcasting?

My question is about a special case of the super class Animal. 1. My Animal can moveForward() and eat(). 2. Seal extends Animal. 3. Dog extends Animal. 4. And there's a special creature that also ...
2
votes
1answer
52 views

Handling Types for Real and Complex Matrices in a BLAS Wrapper

I come from a C background and I'm now learning OOP with C++. As an exercise (so please don't just say "this already exists"), I want to implement a wrapper for BLAS that will let the user write ...
0
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2answers
221 views

Question about casting a class in Java with generics

In Java 6 Class<? extends ArrayList<?>> a = ArrayList.class; gives and error, but Class<? extends ArrayList<?>> b = (Class<? extends ...
-1
votes
3answers
812 views

Is converting/casting a boolean to int a good idea? [closed]

Note: Even though this contains Python, it's not specifically about Python. It's more generally about expecting a certain behaviour from a language which is not necessarily the same across ...
6
votes
6answers
1k views

Would a “downcast if block” be a reasonable language feature?

Consider the following "if cast": class A { public void f1() { ... } } class B : A { public void f2() { ... } } A a = foo(); // might return A or B if ( a is B ) { // Inside block, ...
1
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1answer
48 views

Removing dependencies on subclass-specific behavior

I have a Message class which can contain multiple types of payloads (or sometimes no payload), each derived from a common Payload class. However, this becomes problematic because the Message class ...
5
votes
2answers
321 views

Is there a name for the number of values a variable can take? [closed]

For example, a bit or a boolean can be either 0 or 1 so the number 2 is associated with it. Similarly, for a byte which is 8 bits, the maximum number of different assignments would be 2^8. Is there a ...
16
votes
9answers
19k views

Type Casting variables in PHP: Is there a practical example?

PHP, as most of us know, has weak typing. For those who don't, PHP.net says: PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined ...
1
vote
1answer
244 views

When is type coercion a good idea?

When do you want (on purpose) to coerce type in JavaScript? I mean, beyond comparing strings and numbers, when does it benefit something you're building? Examples of type coercion: "The answer is " ...
16
votes
4answers
937 views

What is casting supposed to mean?

When coding in low level languages like C I find that casting sometimes means 'reinterpret these bytes as if it had always been of this other type' and at other times as 'convert this value ...
1
vote
1answer
185 views

Loose typing not applied to objects

I have very little experience working with classes and object. I work in a loosely typed language, PHP. I was working with a SimpleXML object and ran into a problem where I was trying to do math with ...
7
votes
8answers
6k views

c style casts or c++ style casts

So, what do you use? int anInt = (int)aFloat; or int anInt = static_cast<int>(aFloat); // and its brethren And, more importantly, why?
-3
votes
1answer
223 views

Casting from string to integer and the vica versa [closed]

I am trying to cast in Java from string to integer and the other way around but the compiler is complaining about this. My question is: Is this the matter of compiler or Java programming language ...
1
vote
2answers
956 views

Type parameterized methods to avoid casting

In a library I am developing I have a factory method that looks a bit like: public <T> T instantiate(Type targetType) { return ...; } I am using a type parameterized method to avoid that ...
0
votes
2answers
166 views

Boolean-Integer Typecasting to Replace Conditional

When choosing a value based off of 2 boolean values in this format var foo:int; if (X){ foo = 50; } else if (Y){ foo = -50; } else { foo = 0; } I discovered that I can condense this ...
7
votes
2answers
471 views

implement cons function in Java - type safety question

I am working on a small functional library written in Java, which mimics the a functional style of programming. I am stuck with a undesirable type cast in one of my method definitions and would love ...
1
vote
2answers
802 views

C++ Typecasting VS performance

Let's say we're designing a video game. We have some sprites on the map and we want to call some method of the particular sprite at some particular position. We are using one broadly-known C++ ...
4
votes
2answers
269 views

Alternatives to type casting in your domain

In my Domain I have an entity Activity which has a list of ITasks. Each implementation of this task has it's own properties beside the implementation of ITask itself. Now each operation of the ...
2
votes
1answer
2k views

Java default Integer value is int

My code looks like this import java.util.Scanner; public class StudentGrades { public static void main(String[] argv) { Scanner keyboard = new Scanner(System.in); byte q1 = ...
8
votes
3answers
2k views

Is there a difference between casting and converting types in imperative programming languages?

The question came up in a discussion at StackOverflow. Is there a clean distinction between the two concepts cast and convert (concerning the type of an object), or are these two words describing ...