I am a bit confused about how specific one must be with arguments when declaring a function. I'll show you two functions from the book I'm using to learn C to show you what I mean.
Example 1 (greatest common denominator function):
Code:
void gcd (int u, int v) {
int temp;
printf ( "
[Code] ....
So in that function, there are exactly two arguments, because that's how many arguments the algorithm to find the gcd takes. No problem there, makes sense to me. Then further in the chapter on functions I run into this,
Example 2 (square root function):
Code:
float absoluteValue (float x) {
if ( x < 0 )
x = -x;
return x;
[Code] ....
In this second example, we have a square root function that is preceded by an absolute value function. The absolute value function has the one argument, "float x", however when this function is called within the square root function, the arguments "guess * guess * -x" are passed to it. I'm confused how this absolute value function is working with all of that inside it, when it was originally declared with just "x." The only possibility I can think of is that this expression is treated as a single unit, but I'm not sure.
This is a c program that is failing to compile. The error occurs in the calcLabs() function. The error called out is (btw, I'm using VS 2010): Error4error C2143: syntax error : missing ';' before 'type'
I don't understand why the compiler is not letting me declare variables in the calcLabs() function!
I'm just wondering, why you have to set the length of the inner arrays declaring a function. In which moment does the code needs to be sure about the length of the inner arrays accessing an cell?
I came up with this question realizing the elements of the outer array beeing pointers to the first value of each inner array. Therefore I can access e.g. the first first element of the second inner array like this:
**(arr + 1) ...regardless of the length of any array to my mind.
so in declaring a display function prototype only that displays a student test scores in the format (student name tab number of scores tab test scores )
is this right?
#ifndef STUDENTTESTSCORES_H #define STUDENTTESTSCORES_H #include <string> using namespace std; class StudentTestScores{ private:
[Code]...
and also how do we call the display function if it is in a class from the header file onto the main cpp file.
I am doing a problem where I need to use arrays of string objects that hold 5 student names, an array of one character to hold the five students' letter grades and five arrays of doubles to hold each student's set of test scores and average score.
When I try to run it, I get these five errors.
error C2660: 'getTestScore' : function does not take 3 arguments : line 39 error C2660: 'getTestScore' : function does not take 3 arguments : line 45 error C2660: 'getTestScore' : function does not take 3 arguments : line 51 error C2660: 'getTestScore' : function does not take 3 arguments : line 57 error C2660: 'getTestScore' : function does not take 3 arguments : line 63
I am actually developing an nginx module in C.I am not to bad in C, but i got a big problem to pass argument to a vadiadic function.This function look like the well good old printf, but you put a buffer as first argument, the last address to stop to put data as second argument (in my case it is the last adress of disponible memory), a string that look like one in printf, an the other argument after.Here is the problem, the 4th last argument does not have the good value. In fact, It seem to be random value from memory. I Use gcc (Debian 4.9.1-19) 4.9.1.
I'm trying to create a callback wrapper for pointers to member functions of any class by using templates, std::function and std::bind. This will be used to send incoming sf::Event's to classes who register callbacks with an event manager. I based my code off of the example on this page: URL.....Here's what I have:
class EventCallback { std::function<bool(const sf::Event&)> func;
How this code work bcoz when pointer variable assigned in called function and how different values get as resultant output, ans 2 97 for below code. How the code wil execute so that i can validate ans
#include <stdio.h> int main() { int i = 97, *p = &i; foo(&i); printf("%d ", *p);
What I have is a main function that takes input characters from the command prompt during the main function call, and coverts it to an integer array a using atoi. (starting at the 2nd character - the 1st is reserved for another call that I plan to reference later, and the 0th is obviously the ./function). A function is then called to find the mode of an array (the range of values in the array is 1-30). Now, when I run the whole thing, I get a segmentation fault (core dumped) for even number of arguments. It's late and I've been staring at it for too long...
Code: #include <stdio.h> #include <stdlib.h> int get_mode(int a[], int count);
I'm not a programmer, at least, not a good one. I'm a researcher and I need to implement this function and test it and use it for my research. I tested some clustering methods in JAVA and Matlab and also I want to test it on C. I don't know too much about programming, especially about C, I know nothing. I tried to implement some basic methods but I failed.
It's all about K-Means Algorithm. I'm working on a disease and I'm trying to find ways to early diagnosis. Anyway, these are details. The thing is, I found a 'free to use' function but I don't know how can I use it. I tried to learn something from Net, I downloaded a compiler, I paste the code and I get many errors... And I heard that I have to do some "calling function" stuff but I don't know how to..
The code is in the link below: URL....It's not imperative that using this function, it can be another one but it had to written in C.
error C2660: 'Add' : function does not take 0 arguments error C2660: 'Subtract' : function does not take 0 arguments error C2660: 'Multiply' : function does not take 0 arguments error C2660: 'Divide' : function does not take 0 arguments
I am working on a project in a group at a university. We are creating a GUI in Java where the user can enter parameters. Then we want to be able to pass these parameters to a function inside our C/C++ program, that does the rest. How do I do this? So far I have managed to call a simple helloworld-function by using JNI, dll and a javah tool that create a header file from a java file. I define the helloworld-function in C and call it from Java.
Java file:
package helloworld; public class HelloWorld { private native void print(); public static void main(String[] args) {
[Code] ....
My problem is that I do not know how to call the helloworld-function with parameters. I guess that this is a special case when using JNI and a . dll. How do I pass simple char- and int-arguments from the Java class to the helloworld-C-function?
I keep getting this error in my code. I believe it is because to use pow(x,y) both x and y have to be double, but how do i put that into my formula under calculations?
#include <iostream> #include <cmath> #include <iomanip> #include <string> #include <fstream> using namespace std; int main() { // Declaration section: Declaring all variables.
I have a button that calls a delete stored procedure with only two parameters. I can run the stored procedure via SQL manager and know it works. But, when I call the stored procedure from a sqldatasource on the .aspx page I get this error: Procedure or function has too many arguments specified.
I need to create the following brain damaging abomination:
I need a function pointer type to a function that has an argument of the same function pointer type and returns the same function pointer type.
The purpose is to enable a type of subroutine threading scheme for a small application specific scripting language. The question could just as well have been posted to the C forum.
This syntax works, but Payload is a generic type which I can coerce into the right pointer type via a cast. This is ugly IMHO. I could also hide it as a pointer in the FlipState class since I've forward declared this.
But this is an extra indirection in a performance critical part of the code, and also ugly.
Code: class FlipState ; typedef PayLoad (*FuncPtr) (FlipState *fs, PayLoad P) ; This syntax blows chunks using gcc on the other hand. Code: class FlipState ; typedef FuncPtr (*FuncPtr) (FlipState *fs, FuncPtr P) ;
[Code] .....
This is hardly surprising. The compiler could not possibly understand what I was defining in the typedef. I think what I need is some kind of way to forward declare a function pointer type and then redefine it properly.
Is such a think even possible or am I just SOL? This one is mind boggling. We know how to do this with classes or other complex data types, but the syntax eludes me for both C++ and C.
As we know in C there is no checking if values passed to a function that takes enum are correct, that is if they have been defined in this enum. Example from Enums in C | Occasionally sane ([code] tags don't work on my fx 18.0.1 this is why I put in on pb): [URL] ......
Here c - How to check if an enum variable is valid? - Stack Overflow they say that common convention is add check whether value passed as the parameter is not bigger than the maximum value in enum. But how about situations when enum is composed of numbers from 1-20 and then from 500-510?
Say I have a function pointer with this definition:
void ( *pressFunc ) ( void*, void* );
And i did this function:
void functionWithOneArg ( void* testPtr );
And i did this
pressFunc = &functionWithOneArg;
One. Would C actually let me do this? ( Assigning a function with one argument to a function with two )
Two. If so, what would happen to the second argument that is passed the function when its called? Does it just get 'cut off' and only the first argument is passed?
#include <iostream> // For stream I/O using namespace std; int function(int a) { return a; } int main() { function(int b); }
Why is creating a variable inside the function argument list not allowed. Any reason other then for the language syntax or just for the language syntax?
I have some trouble with DLL. I created a dll with function
double square(const double * args)
and then in my application defines
typedef double (*MyFunct)(const double *args);
I use LoadLibrary and GetProcAddress to get the function address and cast it to MyFunct. Everything works fine except that when I pass a double *, for example 0x08800350, to the DLL function, the argument becomes totally something else, for example, 0x0aa00460.
I have no clue what happens to the argument value.
