Why does division result in zero instead of a decimal?

Why does division result in zero instead of a decimal?

Teaching myself C and finding that when I do an equation for a temp conversion it won't work unless I change the fraction to a decimal. ie,tempC=(.555*(tempF-32)) will work but tempC=((5/9)*(tempF-32)) won't work. Why?According to C Prime

Default constructor with empty brackets

Default constructor with empty brackets

Is there any good reason that an empty set of round brackets (parentheses) isn't valid for calling the default constructor in C++?MyObject object; // ok - default ctorMyObject object(blah); // okMyObject object(); // errorI seem to typ

Using std::unique_ptr for Windows HANDLEs

Using std::unique_ptr for Windows HANDLEs

I am attempting to use std::unique_ptrs to manage Windows HANDLEs in an exception-safe manner.First I tried:struct HandleDeleter{ void operator()( HANDLE handle ) { if( handle ) { FindVolumeClose( handle )

When do I need to declare my own destructor?

When do I need to declare my own destructor?

class Point {public: float x,y; Point() {} Point(float,float); Point operator + (Point); Point operator * (double); void rotate_p(float); void render_p(Point*); void sub(float); float get_dist();//get_distance}

Forward declare a struct in Objective-C

Forward declare a struct in Objective-C

I'm creating a protocol, and one of the parameters to a method I'm defining is a CMTime*. I would like to forward declare CMTime as opposed to including it. However, I've tried @class CMTime and it complains that it is redefined elsewhere a

Static keyword in function parameter

Static keyword in function parameter

I've just found this function definition in some embedded code:float round_float_to_4(static float inputval);I'm familiar with other uses for static (global variables, functions and local variables), but this is the first time I see it as s

Why C# compiler does not allows private property setters in interfaces?

Why C# compiler does not allows private property setters in interfaces?

In certain scenario like a MVVM view-model, I sometimes needs to have private setter as the view-model exposes a state that can only be modified internally.So is this wrong to need a private setter on an interface? (and I mean not particula

How do you handle strings in C++?

How do you handle strings in C++?

Which is your favorite way to go with strings in C++? A C-style array of chars? Or wchar_t? CString, std::basic_string, std::string, BSTR or CComBSTR?Certainly each of these has its own area of application, but anyway, which is your favorit

How do i find out the JDK version Eclipse is using?

How do i find out the JDK version Eclipse is using?

I see JRE all over the place, but i can not be sure which JDK is compiling my code. How do i find out? 1:Actually Eclipse has its own compiler. You can develop java apps using only the JRE and Eclipse 2:You can still check/set which J

What is the _REENTRANT flag?

What is the _REENTRANT flag?

which compiling a multithreaded program we use gcc like below:gcc -lpthread -D_REENTRANT -o someprogram someprogram.cwhat exactly is the flag -D_REENTRANT doing over here? 1:Defining _REENTRANT causes the compiler to use thread safe (i.e

Where are Java final local variables stored?

Where are Java final local variables stored?

Take the following example:public void init() { final Environment env = new Environment(); Runtime.getRuntime().addShutdownHook(new Thread() { public void run() { env.close(); } });}Firstly, where is env

public static final variable in an imported java class

public static final variable in an imported java class

I happen to come across a Java code at my work place. Here's the scenario: There are 2 classes - ClassA and ClassB.ClassA has nothing except 4 public static final string values inside it. Its purpose is to use those values like ClassA.varia

Why first element is destroyed?

Why first element is destroyed?

I have a piece of code like this:class Data{ public: Data(const std::vector &_data) { my_data = _data; } private: std::vector my_data;};int main(){ std::vector> vec = { std::shared_ptr(

Is there a way to improve multicore / multiprocessor performance of the Java compiler?

Is there a way to improve multicore / multiprocessor performance of the Java compiler?

My coworker noticed that when javac is compiling it only utilizes a single core. Is there anything like the -j command with the gcc for Java that will allow us to distribute the compiler workload across cores or processors? If not, do you t

How can I use a Swift enum as a Dictionary key? (Conforming to Equatable)

How can I use a Swift enum as a Dictionary key? (Conforming to Equatable)

I've defined an enum to represent a selection of a "station"; stations are defined by a unique positive integer, so I've created the following enum to allow negative values to represent special selections:enum StationSelector : Printable {

Return type deduction for in-class friend functions

Return type deduction for in-class friend functions

Here is a little experiment with return type deduction for in-class friend functions (using Clang 3.4 SVN and g++ 4.8.1 with std=c++1y in both cases) that is not documented in the linked working paper#include struct A{ int a_; friend

C Language: what does the .mm extension stand for?

C Language: what does the .mm extension stand for?

A project with some Objective-C has a few C classes with the implementation files having a .mm extension.file.hfile.mmWhat does the .mm mean? Shouldn't it just be .m? 1:The extension .mm is the extension for the C++ compilation unit expe

Typescript Function Interface

Typescript Function Interface

Why doesn't Typescript warn me that the function I am defining does not match the interface declaration, but it does warn me if I try to invoke the function.interface IFormatter { (data: string, toUpper : boolean): string;};//Compiler do

Reverse Linked List Recursively

Reverse Linked List Recursively

I have a Node defined in Linked List as: typedef struct abc{ int id; struct abc *next; }node;I want to reverse a Linked List recursively.I am passing the head pointer to the function. My function definition looks like:node *rev

Java unbound wildcard generics

Java unbound wildcard generics

Are there any advantages of using wildcard-type generics in the Bar class over completely skipping them?public class Foo {}public interface Bar { public void addFoo(Foo foo); public Foo getFoo(String name);} 1:There are multiple ad

What is the difference between these declarations in C?

What is the difference between these declarations in C?

In C and C++ what do the following declarations do?const int * i;int * const i;const volatile int ip;const int *i;Are any of the above declarations wrong?If not what is the meaning and differences between them?What are the useful uses of ab

Etymology of linux commands [closed]

Etymology of linux commands [closed]

Just for fun ... I tend to keep myself alert by looking for serendipitous puzzles throughout the day. One of the things I love about linux is the never-ending amount of cleverness it embodies, from its elegant simplicity all the way to the

Precompiled Headers in Header Files

Precompiled Headers in Header Files

I ran into precompiled headers today for the first time..forever changing my life. I can't believe compiling my C++ code could be that fast. It makes total sense now..Anyway, one thing that is confusing me is that from what I've read so f

What is DispId annotation in c#?

What is DispId annotation in c#?

for examplepublic interface IWMPSettings [DispId(101)] bool autoStart { get; set; } [DispId(102)] int balance { get; set; }is it useful or is it just auto-generated for compiler? 1:In short, yes it is useful,

npm install jsdom error on windows?

npm install jsdom error on windows?

I have installed nodejs on my windows pc. And it was working fine. But when I tried to install jsdom using "npm install jsdom" I was prompoted by this error. node "C:\Program Files\nodejs\node_modules\npm\bin\node-gyp-bin\....\node_module