I want to know if it's valid to use and/or when using the conditional operator.
Example:
value = textBox1.Text;
decimal? qty = (value.Equals("0") || value.Equals("0.0")) ? null : (decimal?)decimal.Parse(value);
i know
Code: (condition) ? true-clause : false-clause
but how do you use an array as the condition, how will the code look?For example i want to write
Code:
string numbers[5] = {"one","two","three","four","five"};
numbers == "one" ? thumb : again; thumb and again will replace something else. Don't worry about them.
how do i say that if the numbers array is representing "one" then it replaces as "thumb", otherwise "again".
So I think I am having syntactical problem with my code.
Code:
int main() {
vector<int> ivec;
int score;
[Code] ....
I get an error from my compiler on the ?10th? line (Nested condition line) that says |19|error: invalid operands of types 'int' and '<unresolved overloaded function type>' to binary 'operator<<'|
The purpose of the program is to take input and store it in a vector and then change the value to be between 1-6. I made this for the purpose of learning about nested conditional operations.
I am trying to use getline as the conditional for a while loop as seen below.
string filename, guard_name;
int call_number;
vector <Seniority> SeniorityList;
ifstream SeniorityFile;
[Code] ....
However, when I compile the code, I get the following error message on the line with the while loop.
error C2780: 'std::basic_istream<_Elem,_Traits>
&std::getline(std::basic_istream<_Elem,_Traits>
&,std::basic_string<_Elem,_Traits,_Alloc>
&)' : expects 2 arguments - 3 provided
The program will be reading in a .csv file, so I need my program to be able to deal with values separated by commas. Is there a reason why it will not accept that conditional statement?
I'm facing a serious problem with udp protocol. I have Master & Slave devices.I did implement the class as the follow pseudo code states
In Master side
while (true)
{
1-send data to slave;
2-get data from slave;
3-apply force;
}
In Slave side
while(true)
{
1-get data from master;
2-if (collision happnes)
send force to the master
}
the problem is in line 2 in Master side. Once I include the line I can't send or receive data. What do you think the problem is?
I'm playing with my final year project, building a game boy emulator in C, and I wanted to try out something to streamline my code base. I'm building against Win32, GNU C and Googles Native Client.There are no platform specific headers or functions in use. What I'm trying to do is have a file that conditionally includes the entry point (so _tmain for Windows etc) based on a preprocessor directive being set/not-set.
[note] I realise I could write both entry point classes in one file and use the preprocessor directive in there, but it's not as neat as a single file calling in one or the other. I figure this should work because I can conditionally include headers for Win/NaCl (providing the signatures match, of course).
I am looking for a way to declare variables at run time which being a static language shouldn't happen. I will explain my situation.
I am upgrading a legacy program that modifies executables (non malicious). I am trying to add 64bit support.
It is a huge project and I understand the majority of it but my issues with how it handles the input data.
It has a struct that certain parameters of the input file is loaded into:
Code:
typedef struct DATA {
DWORD Size;
IMAGE_NT_HEADERS32 Headers;
} _DATA; *PDATA
etc, etc its a huge list.
My problem lies in the fact that I need to change IMAGE_NT_HEADERS_32 to IMAGE_NT_HEADERS64 at runtime.
That DATA struct gets called at least 110 times during runtime.
How I might tackle this? Having a conditional statement repeated that many times seems ridiculous.
I have the following code:
Code:
while (lineread != "
")
{
getline(ifs,lineread);
}
In essence, it reads an input file, line by line until it hits a line only containing a newline character. So if the input text file is:
27
GC0123456
102905908801170--
2034068010201360
3039077011601400
4043086012901400
504709401400
6051010101400
[code]....
It should exit the while loop after hitting line 6. What happens however is that it goes into a perpetual loop and doesnt exit the while loop upon reading line 6.
What I did was changed the code to:
Code: while (lineread != "*")
{
getline(ifs,lineread);
} and the input file to:
27
GC0123456
102905908801170--
2034068010201360
3039077011601400
4043086012901400
[code]....
and finally it stops after line 6. In this case, merely changing the " " conditional character to a simple asterisk character "*" fixes the problem.
However I wish to keep the input text file as is with the newlines, so how do I make it exit the while loop when detecting a as a line?
I'm making a program to draw a trajectory, was using as a basis the tangent, but when I put 90 degrees, the tangent is very large, so I thought of putting an if (angle == 90) did not use the tangent.
the design is right, but after choosing it 90 degrees it stops to draw.
for example
1-30 degrees - draws
2-45 degrees ---- draws
3 draws -90 degrees ---
4-60 degrees --- not drawing
5 --- 80 degrees --- not drawing
*
*
making routine design is presented below:
void Draw() {
glColor3f(1.0, 1.0, 1.0);
glBegin(GL_LINES);
convert(graus);
if (ant){
x=xx;
y=yy;
[code]....
I am getting this message from Valgrind, As far as I can see what it points to is initialized. The memory it is referring to is freed in unload and I was not getting this error until after I added the check function. Valgrind was happy. Here is the code and the error message from Valgrind. I am trying to create a spell checker for an assignment for a online class I am taking. I just want to get this table working correctly before I add it to the rest of the program. The code seems to run fine but I have come to see that dos not mean much in C.
#include "hashTable.h"
#include <stdbool.h>
table_node hash_table[TABLE_LENGTH];
bool loaded = true;
//assigning letters a-z to table nodes for buckets
void key_hash_t( )
[Code] ....
Valgrind error:
arortell@gentoo ~/Development/Projects/C_Projects/Data_Structures/HashTable $ valgrind --leak-check=full --track-origins=yes ./hashTable
==11360== Memcheck, a memory error detector
==11360== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==11360== Using Valgrind-3.9.0 and LibVEX; rerun with -h for copyright info
==11360== Command: ./hashTable
[Code] ....
I want to do conditional compilation based on whether it is windows 7 or windows 8. Here is the code below.
#if (_WIN32_WINNT >= 0x0602) //Condition to check whether it windows 7 or 8 .Based on this we can load msxml 3 or 6.
#import <msxml6.dll>
#else
#import <msxml3.dll>
#endif
Im building the above code in windows 8 machine.
Issue here is _WIN32_WINNT should have a value 0x0602, it means it is running in windows 8 machine.Instead it has a value 0x0601 (Means it is taking windows version as windows 7 defined in sdkddkver.h).Im not sure after installing windows 8 sdk im not able to see any include or lib files in the path below C:Program Files (x86)Microsoft SDKsWindowsv8.0A . but i can see all include and lib files of sdk version v7.0A available although i did not installed it.
I have airport class which should navigate planes, in its list to runways, with method move, theres a method prepare which changes the direction of flight to all planes, always before move is called, move just increments decrement x and y of plane in its list. But after calling two times in row airport->move(), I get screwed and I really dont know wheres the problem. Have I badly initiazed something? Iterator gets invalidated.
Valgrind Stacktrace
Conditional jump or move depends on uninitialised value(s)
==26207== at 0x409601: plane::move() (in /home/xnovak11/Downloads/airport/main)
==26207== by 0x401FBD: airport::move() (in /home/xnovak11/Downloads/airport/main)
==26207== by 0x405FE1: io::start(std::istream&, std:stream&, std:stream&) (in /home/xnovak11/Downloads/airport/main)
This is how I add planes into list in airport
Code:
list<plane*> planes;
list<plane*>::const_iterator planeIterator;
list<plane*>::iterator planeIteratorMoj;
bool airport::addPlane(const plane& p) {
[Code] .....
This is the method where it fails. When I call it once, no problem, after second call I get instead of normal number in cout<<after move<< s1 i get like 8795456 ....
Code:
void airport::move() {
for(planeIteratorMoj = planes.begin(); planeIteratorMoj!= planes.end(); planeIteratorMoj++) {
plane * p1 = (*planeIteratorMoj);
int s,w;
p1->getPosition(s,w);
[Code] .....
I'm doing a refresher for C++ and have gotten to operator overloading. I'm trying to perform an operator overload with the insertion (<<) operator, but I have encountered a problem.
Here's my class [In a header file "Shinigami.h"]
#include<string>
namespace K{
class Quincy;
class Shinigami{
friend std::ostream& operator<<(std::ostream&, const Shinigami&);
[Code] .....
If the operator function is a friend of the 'Shinigami' class, why doesn't it recognize any of it's private members? I need it to be in this file because I'm doing a bit of association with the 'Quincy' class.
I thought it was the namespace, but I included that.
I was asked by a friend about validity of following function prototypes,
void func1(int = 0, int*);
void func2(int = 1, int& = 2);
void func3(int*, int& = 3);
void func4(int& = 4, int* = 0);
void func5(int& = 0, int = 1);
void func6(int = 5, int& = 6, int* = 0);
I think the only prototype that is invalid is func1 because it does not have default parameter on the far right.
The following code writes to a file on either local disk to a remote disk (commented out code) on Windows 7 platform.
Code:
#include <iostream>
#include <fstream>
using namespace std;
int main () {
ofstream outfile;
[Code].....
The documentation does not specify what is a valid filename (path and filename). For example, will the "\server emp" path work on all operating systems to access a samba share? Does the constructor accept forward and backward slashes as folder separator on all operating systems?
How can I write my simple program so if the user enters an invalid number, The program won’t exit? I know I am supposed to use a if (cin) or if (!cin),
But I don’t know where in the program or how I should use it. Right now my Program looks kind of like this:
If (number > 1 && number < 1001)
Go through some function loops
Else
Cout << “invalid number”;
I need to write it so when the user enters an invalid number, the program would Keep asking for the right number until it's given.
Now I have to write a code which would determine whether an Email address is valid or not.
In my exercise a valid address should look like this : ___@___.___.il (___ for any letters)
E.g. Valid address:
something @ something . something . il Invalid: tami @ jce . ac . uk
(without spaces of course)
Code:
#include <iostream>
#include <string.h>
using namespace std;
int isValid (char s[]) {
int length=strlen(s), ind1=0, ind2=0;
[Code] ....
It doesn't work well. It says both addresses are wrong when the 1st one isn't.
So my program is to check if a certain 9x9 sudoku grid is valid. i have to get the input through command argument. so for example.
./a.out sudoku.txt
So we have make my c program to use FILE I/O open and what not
program behavior must be as follow File does not exist.File contains something other than a sequence of 81 integers (too many, too few, non-int).
One or more of the values is not in the range 1..9 Violation of Sudoku rules (this is the big one!) In case 4, you should report the violation (or any one of the violations if there are multiple -- you do not need to exhaustively enumerate all violations).
For example: Row Violation: entries (2,2) and (2,6) are both equal to 7. (Similarly for column and box violations). All i know is that i need to make a 2d 9 by 9 array
Is this a good way of writing this program?I wanted to start fresh with my new code though and a better title.Basically, I took what I learned from my questions in that thread and managed to build a list of musical notes( octaves, frequencies, sharp symbols, basically everything ).
Code:
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#define MAX_NOTES 88 /* 88 keys on a standard piano */
[code]...
I already know the frequencies are correct( they are rounded, but they should be close enough to the value ), but I wasn't so sure about the note labels. Obviously though, I'm not done with this program and I will be adding most of the functions Anduril suggested to take a text file and convert it into music. I just wanted to make sure I had everything correct before moving on. I probably didn't do the GetNextOctave() and GetNextNote() functions very efficiently so need suggestions on those functions also.
I have this piece of code in parts of my path finding algorithm
for( int head; head < q.size(); ++ head ){
walk& w = q[head];
// do manything with w
if( some_condition ) q.push_back( walk( w.x + 1, w.y, head ) );
}
However I notice that sometimes w is cannot be dereferenced. It can but it throws junk number at me. Perhaps the vector is changing it size and move the whole array to a different location. Is there anyway to make sure that w is always valid ?
I just want to use w because of shorter typing and cleaner look not because of performance. I also refrain from using macro.
Entering valid user input?
How can I write my simple program so if the user enters an invalid number, The program won’t exit? I know I am supposed to use a if (cin) or if (!cin), But I don’t know where in the program or how I should use it. Right now my Program looks kind of like this:
If (number > 1 && number < 1001)
Go through some function loops
Else
Cout << “invalid number”;
I need to write it so when the user enters an invalid number, the program Would Keep asking for the right number until it's given.
#define PROJECT_ID ram
#define QUOTES(FILENAME) #FILENAME
#define DATA_VAR_FILENAME(PROJECT_ID) QUOTES(../##PROJECT_ID##_data_var.h)
#define DATA_VAR_FILE(PROJECT_ID) DATA_VAR_FILENAME(PROJECT_ID)
#define CUST_DATA_VAR_FILENAME DATA_VAR_FILE(PROJECT_ID)
When I tried to include CUST_DATA_VAR_FILENAME like below
#include CUST_DATA_VAR_FILENAME
Will get below error
error: pasting "/" and "ram" does not give a valid preprocessing token
Is there a function in C/C++ that can check if a given 8-byte data block is a valid double value in the valid range?
View 7 Replies View RelatedWhy does the following line of code generate error as " pasting / and / doesn't generate a valid reprocessing token"?
Code:
#define comment /##/
int main() {
comment printf("hello");
return 0;
}
if I include iostream twice in my project why is that valid? Wouldn't the linker see that there are two definitions of it and report a error, but it works?
By project I mean in multiple translation units.
I have the below code, the first rich text box works fine but on the second i get the error
An unhandled exception of type 'System.ArgumentException' occurred in System.Windows.Forms.dll
Additional information: File format is not valid.
System.Windows.Forms.RichTextBox rtBox = new System.Windows.Forms.RichTextBox();
rtBox.Rtf = reader["Change_Description"] as string;
Change_Description = rtBox.Text;
System.Windows.Forms.RichTextBox rtBox2 = new System.Windows.Forms.RichTextBox();
rtBox2.Rtf = reader["Change_Justification"] as string;
Change_Justification = rtBox2.Text;