C :: How To Make The Preprocessor Compare Against Constants Defined
Mar 6, 2015was just curios to know if there is a way to make the preprocessor compare against constants defined like this: Code: uint uint_max = -1;
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C# :: For Loops To Make User Defined V Shape Output
Jul 29, 2014Write a program to ask a user to input a symbol from the keyboard and to output that symbol in a n X n/2 sized V where n = the width of the V. You must use a loop to process the data
I am stuck at trying to figure out how to do the actual output formatting. This is where I am sitting currently.
string character = "";
int vheight = 0;
Console.WriteLine("Enter the character you wish to use for your V: ");
[Code]....
so Im really just a bit stumped on how to get the actual V shape to be formatted..
C++ :: How To Use Plus And Negative As Preprocessor Directives
Sep 21, 2014how to use '+', '-', '*' as preprocessor directives??
I want to do the following work.
#define + 10
#define - 20
#define * 30
Visual C++ :: Windows 64 Bit Or 32 Bit Preprocessor Directives?
Jul 1, 2013I want to connect to an SQL Server database using ADO with VC++.
In order to do that you need to import an external dll, like so:
#import "C:Program Files (x86)Common FilesSystemadomsado15.dll"
What if the OS is not 64 bit? That would mean the (x86)-suffix would be incorrect.
how to work around this using certain preprocessor directives?
Something like this, maybe?:
#if 64bit
#import "C:Program Files (x86)Common FilesSystemadomsado15.dll"
#else
#import "C:Program FilesCommon FilesSystemadomsado15.dll"
#endif
C++ :: Command Line Options For Preprocessor Directives
Oct 17, 2014I want to run the following code from the command line:
Code:
#include <iostream>
using namespace std;
#ifdef ABC
const int num = 105;
[Code] ....
But I can not activate the ABC macro from the command line.
I'm trying to use the -d ABC option following the .exe file name, but I could not run the ABC macro.
How can I activate the ABC macro when I run the .exe file from the Windows 7 command line?
C++ :: Sending Constants As Parameters
Nov 21, 2013What's the problem with the following:
Code:
#define K 3;
int max(int a, int b) {
return a>b? a : b;
} int main() {
cout<<max(K, K+3);
return 0;
}
Why is it not allowed, and how is it different from:
Code:
int max(int a, int b) {
return a>b? a : b;
} int main() {
cout<<max(3, 3+3);
return 0;
}
C++ :: Getting Vowels And Constants From String
Nov 18, 2013I am working on a code that is suppose to get vowels and consnants from a string. So far i got up to trying to get the vowels from a string. this is what i have so far:
#include <iostream>
#include <string> // includes go into header
using namespace std;
int getword(string word);
int getvowels(string word);
[Code] .....
C/C++ :: Setting Constants As Attribute?
Apr 3, 2015I would like to know how can i set a constant attribute in the constructor. This attribute is an int value that cannot be changed.
For instance:
class Test {
public:
const int x;
public:
Test(const int val);
[code].....
With this code i get compile error!
C++ :: How To Template Float / Double Constants
Nov 19, 2014I have a templated class that can either use float or double as type.
My question is now: What do I do with constant numbers in the code?
Let's assume I have a multiplication by 0.5:
In the case of float type, I want: 0.5f
In the case of double type, I want: 0.5
One answer would be to check for every constant the type and doing an if/else, but this is very annoying with lots of constants.
The code using these constants infer their type automatically by the assignment, that's why I have to take care of the constants.
C/C++ :: Difference Between Literal And Symbolic Constants?
Jun 29, 2014"A constant, like a variable, is a memory location where a value can be stored. Unlike variables, constants never change in value. You must initialize a constant when it is created. C++ has two types of constants: literal and symbolic.
A literal constant is a value typed directly into your program wherever it is needed. For example, consider the following statement:
long width = 5
This statement assigns the integer variable width the value 5. The 5 in the statement is a literal constant. You can't assign a value to 5, and its value can't be changed.
The values true and false, which are stored in bool variables, also are literal constants.
A symbolic constant is a constant represented by a name, just like a variable. The const keyword precedes the type, name, and initialization. Here's a statement that sets the point reward for killing a zombie:
const int KILL_BONUS = 5000;
Whenever a zombie is dispatched, the player's score is increased by the reward:
playerScore = playerScore + KILL_BONUS;
If you decide later to increase the reward to 10,000 points, you can change the constant KILL_BONUS and it will be reflected throughout the program. If you were to use the literal constant 5000 instead, it would be more difficult to find all the places it is used and change the value. This reduces the potential for error."
what's the difference? Here is a program to demonstrate what I'm having trouble conceptualizing.
#include <iostream>
using namespace std;
int main() {
int width = 10, length = 10;
int area = width * length;
cout << "Width: " << width << endl;
cout << "Length: " << length << endl;
cout << "Area: " << area << endl;
return 0;
}
Now, why would it be harder to go in and changed a regularly defined integer than one defined with the 'const' keyword proceeding it? For example, the width and length variables. My confusion comes from the point that they seem to both simply be variables with a value assigned to them. I feel as if the process of having to change a literal constant's value is synonymous to the process of having to change a symbolic constant's.
C++ :: Displaying Constants As Decimal / Hexadecimal / Letter
Oct 13, 2014I need to write a program in which you do the following:
Define three named constants using the appropriate data types:
DEC_NUM = 65;
HEX_NUM = 0x7a;
LETTER = 'f';
Then display each of these constants in decimal, in hexadecimal, and as a character using cout. Your program will have a total of nine cout statements.
C++ :: How To Implement Symbolic Constants To Factor Out If Else Statements
Feb 17, 2014My assignment is to create a simple stock broker program that ask the user how much they are willing to invest and ask what company they would like to invest in. Finally it outputs how many shares the user will have based on their investment amount. My code is below. My professor said to declare symbolic constants and factor out the if else statements. Ive been struggling trying to understand constant variables. How do I use const variables to factor out the if else statements?
#include <iostream>
#include <cstdlib>
using namespace std;
int main() {
//Declare Variables
const double BAC = 16.7;
const double Citigroup = 49.52;
[code]....
C++ :: Strcmp On Linked List Data And String Constants?
Sep 28, 2013why strcmp() doesn't return true when comparing a string constant with a string that was acquired via a linked list. By the way, the data in the linked list was taken from a text file. Does that imply that there's a new line () character in the string from the linked list?
Code:
struct Node{
char ACNO[15];
struct Node *next;
[Code]....
C :: Why Constants And Variables Stored In Memory In Opposite Order Called
May 23, 2014I'm playing around and wrote a tiny program.
Code:
char bracketin[] = "thisgetsbracketed.txt";
char bracketout[] = "bracketed.txt";
char testwalk[10] = "12345678";
[Code]....
I'm incrementing the pointer to buffer 150 bytes beyond its reserved 50. I see testwalk, followed by bracketout, followed by bracketin printed by the overflow on buffer.
The memory locations are ordered descending from their call order. Why is this the case?
One would think that they would be written in ascending order as I call them. I can only assume that they're compiled bottom up - where could I read about this process?
C++ :: Using Map Against Defined Input?
Sep 16, 2013What I want to do is have a defined string as the input and use that to run it against the keys, so I can pull out the values. I have some functions beneath for searching, a possibility would be to parse the input and use something along those lines.
I would like to try and use a map for this.
#include <iostream>
#include <map>
#include <string>
[Code].....
C :: Printf Int That Was Defined In Another Function?
Feb 26, 2013I'm making my way through most of this assignment that I have, but now it seems like I've run into a bit of a roadblock. The issue that I'm having is not being able to printf a series of ints that I thought I had previously defined in another function. I don't want to clog up this post with the entire code, so I'll just post one function that defined an int to give an example. I will upload the whole thing upon request however.
Code:
#include <stdio.h>
#include <stdlib.h>
//Prototypes
int AGrade1(int* grade1);
int AGrade2(int* grade2);
int AGrade3(int* grade3);
[Code] .....
I've tried many many things, but I just cant figure it out. This is what it's supposed to look like.
Assignment Grades:
18 12 17 15 20 13
20 18
C :: Testing If A Macro Is Defined To A Value?
Jan 16, 2015Say I have something lke
Code:
#define FOO BAR
#if FOO == BAR
doX();
#else
doY();
#endif
This causes doX(); to be executed. But the intent is to have doY(); be run. I'm guessing this is because BAR is undefined and therefore blank, so blank equals blank. Is there some way to compare the symbol FOO was set to instead of its value, BAR?
C++ :: Determine If A Function Has Been Defined
Apr 8, 2013I would like to make a handler for input events, but not be required to define all the functions.For example, if I had
void mouseDown(int button,vec2 pos);
void mouseUp(int button,vec2 pos);
static void mouseStateHandle(int button,int state,int x,int y) {
switch(state){
case DOWN:
[code]....
in the 'mouseStateHandle' function? I don't know enough about C++ to be able to come up with a solution.
C++ :: Using Enum Defined In Class
Apr 1, 2013I am trying to write a game in C++ with SDL, and I have a class that allows me to handle events. The class is actually really simple: It takes the SDL_Event, then 2 variables from 2 different enum to determine for which Event and which Key should be checked, and then a variable that will be modified if the event happens. Here is the class
EventParser.h
#include "SDL.h"
#include "SDL_opengl.h"
template<class T>
[Code]...
As of yet the variable only changes if the Left key has been released, it will be extended if the error has been solved.
Then, in my main.cpp file I define the Event and the EventParser as
SDL_Event event;
EventParser<float> ep;
And in a loop, the parseEvent function is called like this:
ep.parseEvent(event, ep.KeyUp, ep.LEFT, &xVariable);
However I get a linker error (not the first one I got when programming this game)
error LNK2019: unresolved external symbol "public: void __thiscall EventParser<float>::parseEvent(union SDL_Event,enum EventParser<float>::EventType,enum EventParser<float>::KbdKey,float *)" (?parseEvent@?$EventParser@M@@QAEXTSDL_Event@@W4EventType@1@W4KbdKey@1@PAM@Z) referenced in function _SDL_mainC:UsersPrideRageDocumentsVisual Studio 2012ProjectsSDL_TestSDL_Testmain.objSDL_Template
C++ :: Error LNK2005 - Already Defined
Jan 29, 2014I have 4 files:
def.h
mms.h
mms.cpp
runMms.cpp
In the first one I define a struct. In the second I declare/create a new class called mms and I include "def.h". The third one is the cpp file of the class and I include in it "mms.h" (no, I don't include in it "def.h"). The fourth and last has the 'main' and I include in it "mms.h"
For some reason I'm getting the "error: lnk2005 alread defined ..." I know it usually has to do with putting some header file or definitions twice but I can't see where I got wrong.
C++ :: Linking Errors - Xxx Already Defined
Sep 7, 2012I am forced to have the deceleration of a class template in the .h file.
See here: [URL] ....
This works perfectly fine, as long as i #inlcude the header file only in ONE .cpp file.
The moment i #inlude it in several .cpp files, i get LNK2005 already-defined errors.
a.obj : error LNK2005: "public: unsigned int * __thiscall theclass::themthod(void)" (?xxx@theclass@@QAEPAIXZ) already defined in b.obj
I would have assumed inclusion guards can protect me from this, but wrong.
C++ :: Classes Defined With Struct And Union
Mar 12, 2013Classes defined with struct and union
Classes can be defined not only with keyword class, but also with keywords struct and union.
The concepts of class and data structure are so similar that both keywords (struct and class) can be used in C++ to declare classes (i.e. structs can also have function members in C++, not only data members). The only difference between both is that members of classes declared with the keyword struct have public access by default, while members of classes declared with the keyword class have private access. For all other purposes both keywords are equivalent.
The concept of unions is different from that of classes declared with struct and class, since unions only store one data member at a time, but nevertheless they are also classes and can thus also hold function members. The default access in union classes is public.
The above is a statement taken from a C++ tutorial. So I understand classes a bit better now but the above quote doesnt make too much sense. Is it saying that you can have a class within a class?
C :: Signal Function Defined Twice With No Error?
Dec 13, 2013I'm using a library in my code in a file called "my_signal.c". In this file I've defined this function:
Code:
Sigfunc * signal(int signo, Sigfunc *func){
struct sigaction act, oact;
...
}
Since the signal function is also in file signal.h and I included it in "my_sygnal.h" file, I'm wondering why the compiler did not say anything about this "double declaration" of the function with the same name.
C :: User Defined Array Size
Jul 23, 2014The instructions call for the user to define the size of the array and all I have ever done is use a predefined size for the array and then let the user fill it. Here is what I have so far:
Code:
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void Display (void);
void random (int *, int);
void Ascending (int *, int);
void Descending (int *, int);
[code]....
C++ :: STL Set Orderinf User Defined Objects
Mar 4, 2014#include<iostream>
using namespace std;
#include<set>
class person{
int age;
[Code] ....
When I executed the above code it displays
Age is 37
Age is 25
Here I have defined operator< so that set can identify the order of person objects. I am clueless how set could identify that
person p[3]={person(25),person(37),person(25)};
I have provided one duplicated object with age 25
I havent overloaded == operator also,then how it could identify?
C++ :: Calling A Function With Dynamically Defined Name
Feb 19, 2013Is there a way to call a function whose name is defined in a file-stored-list?
In other words: The caller doesn't know in compile time the name of the function.
I'm not talking about polymorphism.
The problem is: I have a list of function names stored in a file, that may change every now and then, and I'd like to call them in the sequence they appear in that list.