C++ :: Function Argument - Variable Is Being Used Without Initialized
Jan 27, 2015
I get an error when i try to compile this code. I tried to allocate memory in main function and that works. But why it doesn't work in function? I think that there is something wrong with function argument, but not sure.
Code:
#include <iostream>
#include <fstream>
using namespace std;
struct Word
I was wondering if one could write a function that could accept one or the other variable type.
Ex: I have 2 arrays, int** and double**, and a function
Code: void PGMWrite(double** Matrix, int Matrix_dimension){.....}
Is there any way to change the function to
Code: void PGMWrite(int** Matrix || double** Matrix, int Matrix_dimension){.....}
And then have some sort of type identifier in the function that picks the correct section via an if loop? If so how, and how would I identify in the function if the input it type double or int?
in a header file and the header file is included in several C files.
Questions:
At run time,
Is there just one copy of the const variable my_fl_dark_gray or are there multiple copies for the multiple C files?If a function uses the const variable, does the initialization statement "my_fl_dark_gray=fl_color_cube(...);" run every time the function is called or does it just run once and then when the function is called it just uses the value stored in memory?
I am writing a program to calculate a rectangle's area.
Eg. Enter top left point: 1 1 (User input) Enter bottom right point: 2 -1 (User input) Top Left x = 1.000000 y: 1.000000 Bottom Right x = 2.000000 y: -1.000000 Area = 2.000000 (Program output)
It keeps on prompting me my variable r is being used without being initialized, when I think I already did so.
I've created a program meant for submission for my final project but when i ran it, it shows that the variable being used without being initialized for quite a few time. My program is below.
when i compile my code i get this error : "error : variable-sized object 'largeArray2' may not be initialized"
Code:
float give_coefficients_routh_table_and_fill_two_first_lines(int denominator_degree) { float largeArray2[20][20] = {0}; int l = 0; int c = 0; int e = denominator_degree ; for ( e = denominator_degree; e>=0; e--)
Under visual studio, this is a typical run time error,
Code: void func(int x){ x = 3; } int main() { int x; func(x); }
When x is passed to the function func, it is not initialized. But my question is that why it should be an error? On the other hand, if I change the definition of func a little bit like this,
Code: void func(int& x) { *x = 3; } int main() { int x; func(&x); }
Now in main, x is still not initialized, but this time there isn't a run time error like "the variable is being used without being initialized. Why?
I am trying to generate a couple of vectors, but the exact number of vectors that will be needed can only be determined at runtime. Therefore I had the idea to use a macro call and text substitution in order to declare the necessary number of vectors. Unfortunately, the arguments of a macro call are always (as far as I know) considered text only. So, the loop in my example below in which I am trying to generate the following code:
error C3867: 'WordParsor::Form1::PutUpfrmIO': function call missing argument list; use '&WordParsor::Form1::PutUpfrmIO' to create a pointer to memberc:userskingc++wordparsorwordparsorForm1.h... and the suggestion fix generate another error.
One person suggested the gcroot<> object wrapper... but I do not know how to modify/declair the function or its argument type.
I am writing a program in which a Fucntion has to be wriiten to parse the Command Line . When I include Code for parsing in main fuction iteslf ,its run ok . But I want to make a fucntion of that code and call it from main ,than it show Segmentation error .
By using Debugging I found Some thing is mess with " -m" Parameter of Command line , But Cant Rectify it ..
Code: int main (int argc, char *argv[]){ //get_parameter_value(argc,argv); // buffer[packet_size+1]= char ("'"); while (argc > 1) { if (argv[h][0] == '-')
How to pass an int that I got from user input into a function to use it. I am trying to print out the words to a string of numbers.
I got the input from user. I got an absolute value of the input. I then separate the string into individual digits and name them. I can print these out. Then I started my if statement by checking if the original input was zero, and if it is, printing zero and exiting. Then I an trying to pass the digits into a switch function and this is where I go off the rails.
I was reading about void as function argument, but I did not fully understand it's meaning in C.
In C++ void foo(void) {} and void foo() {}
are the same. It means no arguments for foo function. But in C it's different. First function means the same as in C++, but second means
In C, an empty parameter list means that the number and type of the function arguments are unknown. But if it is unknown you can't use this arguments if user specifies same. Because here are no variables to store them. So doesn't result are the some? You do not get any arguments. O do I can get this arguments from some hidden variable?
For example.
void foo() { printf("%d", var); } foo(5);
It is very unclear for me. Do this apply to main function too?
int main(void) int main()
or can I use arguments given to int main() like given to int main(int argc, char* argv[])
I am using a small robotic-car that is controlled by writing C/C++ codes under Linux. I need to use a particular function from the library provided by the manufacturer. The relevant API documentation for the function is:
Returns: BASE_OK RS232 data acquisition success BASE_BASE_232_GETDATA_ERR RS232 data acquisition failure
I have trouble writing the relevant code in the main program that invokes this function. Here is a snippet of what I have tried:
# include "Baseboard.h" int main () { Baseboard _Baseboard; // Class name is Baseboard char *msg ;
[Code] ......
The part where I am uncertain is how to handle the char pointer "msg" in the declaration, function call and referencing. According to the documentation, the char pointer "msg" is the output of the function so I presume that is is somehow dynamically allocated. Am I handling the char pointer properly in the declaration, function call and referencing parts?
Another related question I have is: I am printing out the value of the variable "dummy". I always get 0 for it. Since the variable "dummy" is an enum of type BASEBOARD_ERROR_KIND which can take on two values (first value represents success and the second failure), it is alright to get a integer value of 0 for it if the function call was successful ? (I do not have much experience with using enums so this is a enum-related question on whether we can get an integer value representing the first enum value) .
how can i pass an array as an argument to the function? in getCoin() fcn, I am supposed to pass coins array as an argument to the function. fcn prompts user to enter coin(Date, Type and Country). values entered by user are read and assigned to the coins array. I tried the code below.
//# include "Coins.h"; #include <iostream> #include <string> using namespace std;