C++ :: Define A Class Arc Which Draws A Part Of Ellipse
Apr 24, 2014
The exercise is : Define a class Arc, which draws a part of an ellipse.
Hint: fl_arc()
And the body of the class ellipse is as follows in the book (PPP):
struct Ellipse :Shape {
Ellipse(Point p, int w, int h); //center, max and min distance from center
void draw_lines()const;
Point center()const;
Point focus1()const;
Point focus2()const;
[Code] ....
And the fl_arc() probably is part of FLTK which I've installed it on my machine.
Now the problem here is that while I don't can see the full version of the body of the ellipse how to do this exercise?
class Base { char * ptr; public: Base(){} Base(char * str)
[code].....
Obj1 is a derived class object where base class char pointer is initialized with "singh" and derived class char pointer is initilized with "sunil". I want to create Obj2 out of Obj1. Separate memory should be created for Obj2 char pointer (base part and derived part as well) and that should be initialized with the strings contained in Obj1.
Here the problem is: Derived class part can be initialized with copy constructor. How to initialize the base class char poniter of Obj2 with the base class part of Obj1. char pointers in both the classes are private.
I tried using initializer list but could not succeed.
when vpStatus is nonsense and unknown, the vaporPressure should not have a value; and if I calculate out a value for vaporPressure, the vpStatus can be set as known.
I am wondering if there is any set, pair or other structure can hold this two members together, so that when I change one's value, the other guy will also change accordingly.
Define a class for a type called CounterType. An object of this type is used to count things, so it records a count that is a non-negative whole number.
Include a mutator function that sets the counter to a count given as an argument. Include member functions to increase the count by one and to decrease the count by one. Be sure that no member function allows the value of the counter to become negative.Also, include a member function that returns the current count value and one that outputs the count. Embed your class definition in a test program and run sufficient tests to verify it all works correctly.
it seems that I cannot define a method of an inner nested class if it is a private class. for example:
class outter { class nested { void foo ( void ) {} // okay - but is this inline? } void inner::foo( void ) {} // not okay - cannot define inside another class } void outter::inner::foo( void ) {} // not okay - 'nested' class is private!
what I want to know is, is there another way to define an inner class's method? and if not, is it eternally doomed to be inline because it has to be declared inside it's own class declaration?
Define a class for a type called CounterType. An object of this type is used to count things, so it records a count that is a non-negative whole number.
Include a mutator function that sets the counter to a count given as an argument. Include member functions to increase the count by one and to decrease the count by one.
Be sure that no member function allows the value of the counter to become negative.
Also, include a member function that returns the current count value and one that outputs the count. Embed your class definition in a test program and run sufficient tests to verify it all works correctly.
For example, in a header file A.h, I define an abstract class,
Code:
// A.h class A { public: virtual void foo() = 0; private: static int _x; };
How'd I initialize static member data _x?Normally, we initialize a static member data in a cpp file. However, there is not cpp file for A.h. If I intialize _x in header file, there will be linker errors like mulitple defined symbols. What is appropriate way to do that?
I would like to define a templated class while implementing default value on templated arguments. I don't know how to do that with string templated variables.
For exemple:
Code: template <class T> class A { public: A() { version = ???? } std::string_base<T> version; };
I don't want to pass the default value as parameter of the constructor. how I can do this?
And I want to create a function to print either c or x. However, I don't want to just use a switch or something to figure this out, I want to reference which part I'm outputting.
Now here's the twist
vector<data> dataList;
I need to access element x or c in the vector, but all I pass is the vector and which element, so that I might have something like:
int count = t1; while(count>counter){ Sleep(delay); Int32::TryParse(textBox2->Text,add); result = result + add; counter = counter + 1;
Problem is that sleep stops all program for specified time, Is there an alternative to sleep that would only stop part of code or can i use sleep different way to specify what it pauses?
Is there any way I can clear only a selected part of the screen? (I'm aware of system("cls"))
For example, when you enter a date, and is wrong, could it just errase that input and only say "Wrong try again" without errasing everything else you where doing?
In this case, a function that only errases what is in the while
I am having a little bit of trouble with what should be a simple part in my code. For some reason it keeps looping the name part of the program and I seem to be passing over the problem in the code.
Here is the code:
#include <iostream> #include <string> using namespace std;
Code: // string::erase #include <iostream> #include <string> int main () { std::string str ("This is an example sentence."); std::cout << str << ' '; str.erase (10,8); std::cout << str << ' ';
Code:
Output:
I don't understand this program. What do these 2 numbers represent? The index of an element in a character array? The 10th character of the array is 'n' and 8th is a "space".
I'm having a problem converting part of a string to an integer.I used strtok to seperate my string and I have also a function for atoi but how to apply it to my strtok function.What i need is to change the char *years to an int.Have a look of what I got:
Code: int main() { char sentence[]="trade_#_2009_#_invest_#_DEALING"; char *word=strtok(sentence, "_#_"); char *year=strtok(NULL, "_#_");; // assigning NULL for previousely where it left off char *definition=strtok(NULL,"_#_"); char *synonyms=strtok(NULL,"_#_");
I have a character array that includes configuration bits that are 0x00, thus when I try and do a strcat it adds the appended string into one of those spots instead of the end of the array.
I'm writting an algorithm which equals to std::to_string. The inttostring part is fine, and the decimal_part too. But when the number digits > 5, the program loops infinitely.
I have a vector of sets, which I am removing any element which contains a certain value. For example, if I was looking for 2:
[0] 1 2 3 [1] 4 5 6
After the program was run, I would be left with just [0]4 5 6.
This is the code I have been using
auto iter = std::remove_if( clauseVector.begin(), clauseVector.end(),[propagator] ( const std::set<int>& i ){ return i.find(propagator) != i.end() ; } ) ; clauseVector.erase( iter, clauseVector.end() ) ;
I want to know, is there any way I can tweak this code so that it only removes one part of the set rather than the whole thing. For example with above example, I would be left with