How can i change or add a cell to an array without knowing its length ? (I mean that I shouldn't know the length I need to make the length dynamic so i can add a cell)we just learned Dynamic assignment(I hope this is the correct name) and Pointers.
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I believe that everything is fine except that I can think of the condition can be inserted inside the parentheses ..
#include <iostream>
using namespace std;
int main() {
int i=0, k=0;
char *string_n, **matrix, temp;
[code].....
I'm writing a program in which I have to use a matrix to represent a file in code. because it's a file, the size of the matrix is undefined, and therefore the matrix has to be dynamic. I found out that my compiler doesn't like dynamic multidimensional arrays, so I was thinking of this matrix as a dynamic (monodimensional) array of other dynamic (monodimensional) arrays. My program (and thus this example) uses unsigned chars.
unsigned char variable=something;
unsigned char**matrix=new unsigned char*[lenghtOfMainArray];
for(int rowNumber=0;rowNumber<lenghtOfArray;rowNumber++)
{
[Code].....
Any way to get the length of a string? I have tried:
str.length
str.size
strlen()
Bob
Code:
// Exercise in string manipulation
#include <iostream>
#include <string>
void prtname(std::string str);
using namespace std;
int main() {
[Code]...
PHP Code:
int processString(xxx)
{
//do something
return non-null terminated string length
}
To make the function work better we change its internals
PHP Code:
int processString(xxx)
{
//do something
return null terminated string length
}
This phenomenon can be observed by use of mutibyte to wide char conversions, string copy , concatenation functions of MS etc ....
Should I minus one in the return value of the second function to match both versions ?
My program allow user to draw lines and the user should know the length of the line that he draw in centimeter (.cm)
I did use
SetMapMode(MM_LOMETRIC) function to convert the device units into logical units
and it works correctly but I don't know how the line length will appear to the user to let him draw in correct length
I think to make the length appear on the mouse when the user draw but I don't know how I calculate and display it.
I'm working with arrays that might have NULL bytes in them and I'm wondering how to determine the length of the array or store it somewhere with the array (strlen() won't work because of the NULL, right?).
I've found advice like store the length of the array in the first byte of the array, but since sizeof(size_t) is 8 should I leave the first 8 bytes for the length?
Would it be better do define my own structure which would store the array and its length? What's the usual way these things are handled in practice?
I was reading in a book I had about C that an array has at the very end a "null character" signifying the end of the string inside it, "/o". So that made me think, "I guess one needs to declare arrays as having 1 extra space than one expects the array to need. I wonder what will happen if I exceed the array length?" So I made a program to test it out. Here is the program/results:
Code:
#include <stdio.h>
int main(void){
char name[3];
printf("
What's your name?
");
scanf("%s", name);
}
[code]....
As you can see my name was able to fit in the array somehow even though I only allocated 3 bytes to the array. I tried again using my legal first name, Benjamin, and it was still able to fit. How is the array able to hold my name when I declared it as only having 3 bytes?
i having a code to pass in array as argument, but the length returned is 1. This is not match with the array size.
int Getsize(int Array[])
{
int len = sizeof(Array)/sizeof(int);
cout << len << "
";
}
int main()
{
int X[] = {45, 12, 54, 83, 41, 36};
getsize(X);
}
I can't find any method of retrieving the length of an array except for doing this:
string first[] = {"a","be","see"};
int length = sizeof(first)/sizeof(first[0])
This is a very unconventional way of getting the length of an array.
first->length() would return 1 because it returns the number of letters in the first element of the array (which actually makes no logical sense).
first.size() would return 1 aswell as it's practically the same thing.
Since getting the length of an array is such a fundamental feat, how come I can't find a decent method of doing it?
Is there no buildt in method for this? If there is not, why has it not been implemented in the std?
I have a program with the following code, and I need to be able to either change the value of any or all of the strlen or to replace one or all with a temp array value. All values of the expression are arrays.
if (::strlen(tc_buf) + ::strlen(maxtime_buf) + ::strlen(" ") < sizeof(localBuf))
I'm trying to make an application and I need the length of the array of a struct. Like this:
struct myStruct {
int integer;
};
myStruct struct[] =
{
1,
2,
};
I want to get how many ints are in the array...
I am working on a c-programm. In this program I have to convert the amount of money I read on two variables into the corret format. I got Euros and cents on 2 ints. But now I want to add both of those variables in a String (char array). Also i want to find out the length of the new char array.
View 2 Replies View RelatedHow can I obtain the length of an array that has been sent throughout a function. In the following code, I obtain "2" as output, while I was expecting "5".
void call(int a[]) {
cout<<sizeof(a)/sizeof(int);
}
int main() {
int* a=new int[5];
call(a);
}
How can I properly call this function so I can obtain the correct array size?
This code snippet compiles and runs fine
Code:
#include <stdio.h>
int main(void) {
int i, a[i];
i=2;
for(int n=0; n<=i; n++)
a[n]=0;
[Code] .....
It prints out 3 "0", but when slightly changed
Code:
#include <stdio.h>
int main(void) {
int i, a[i];
i=200;
for(int n=0; n<=i; n++)
[Code] ....
It compiles fine but core dumps when run, how come? i'm using gcc version 4.4.7, and compiling like this
gcc -std=c99 test.c -o test
The WinAPI has a struct like this for raw input:
Code:
typedef struct tagRAWINPUT { RAWINPUTHEADER header;
union {
RAWMOUSE mouse;
RAWKEYBOARD keyboard;
RAWHID hid;
} data;
[code]...
The definition of the struct doesn't show it but the documentation says that bRawData is variable length. sizeof(RAWINPUT) will not be the correct size when the data field is of RAWHID type so how do you allocate a variable with automatic storage type that has the right size for the entire struct? You can get a header that has the size for the entire struct but how do you actually allocate storage space for the data without using malloc? I've seen some example code that used a char array but that violates aliasing rules and there are also alignment issues with that approach.
How to write a function that receives an integer array along with its length. the function calculates and returns the sum of the squares of all the odd numbers in the array?
View 2 Replies View Relatedi have to read a file with between 5 and 10 pairs of numbers, each on a different line. i can read the file, and wrote something to save the length of the file as a variable, but when i use it i start returning crazy data. the problem is in the do while loop and i want to change the i< in the for loop to "lines" so the code stops when the last digit is read. if i use i<10 the file has extra digits is the file is only 8 or 5 pairs of numbers.
FILE *Fpointout;
FILE *Fpointin = fopen ("test.txt","r"); //read this one
Fpointout = fopen ("out.txt","w"); //write this one
if (Fpointin == NULL) //if no file in source {
printf ("File does not exist."); //tell user it is not there
[Code] .....
I want to ask for a number as an input during runtime and then create an 2-dimensional array of size as specified by user. i.e. if the user inputs 3, the array should be of size 3X3, and likewise...
View 9 Replies View RelatedBut it can the other way around
Code:
static_Array= dynamic_Array;
dynamic_Array = static_Array;
The second statement works and i'm able to print out both arrays with equal values but with the first
[code] static_Array = dynamic_Array;I get incompatible types in assignment of 'int*' to 'int [7]' is the error I get [/code]
We're designing a new software and we want it to be customizable without code. That, for us, mean we can change the software behaviour without re-writing code. All will be developed using C and .NET.
One of our goals is to have what we are calling "dynamic tables". This means that these database tables may have different fields depending on the customization. We got to know it using high-level ERPs like SAP or CRM's system like VTIGER or even SalesForce. Let me give an example:
CUSTOMER TABLE:
FIELDS: ID, NAME, ADDRESS, PHONE.
This would be the standard Customer Table.
Now, a new customer needs to add FINANCE SCORE and RANKING to the database. We them would like to go to our application (not the database itself) and adding these new fields. After that, all of my input forms and reports would start to show and process these new fields.
We want to generate dynamic resource file for VC++ where the data will come from database (Oracle).
For an example, When a user log in the system, at that time if User is an English User, then some data in english language needs to be loaded in vc++ resource file. If the user is French then French data will be loaded into the resource file.
Right now all the data are hard-coded in the resource file but we want to load it dynamically from database, based on the login-user language.
How to do this dynamic implementation as I am not able to find any such concept in google.
I've created a dialog based MFC app which input from user to create that many dynamic controls(Used checkbox to be created dynamically).
After user input that many checkboxes controls are created but if try to click again then not able to delete previous controls and again new no. of controls.
Code snippet to add controls on user input.
RECT rctA;
rctA.top = 51;
rctA.bottom = 80;
CString temp;
m_Edit.GetWindowText(temp);
int noOfControls = _tstoi(temp);
[Code] ....
The goal is to change the status bar (CMFCRibbonStatusBar) icons based on some events. (The old CMFCStatusBar class had the SetPaneIcon() member that easily solves the problem.)
The "improved" CMFCRibbonStatusBarPane has no members to set the icon, other then the constructor. Being a subclass of CMFCRibbonButton, it has SetImageIndex() that sets the icon index in the image list. The MS online support does not mention how and where to set that "list of images". My understanding is that the list belongs to the Button's parent; in this case it is the CMFCRibbonStatusBar, which has no methods to set any image list. How and where am I supposed to set that list of images for the status bar?
Second related question: I have tried to set the pane icon with the CMFCRibbonStatusBarPane() constructor by loading it from an icon resource. The icon appears shortly and then it is replaced by a gray patch. (for tests I also used one of the icons given by the MFC wizard, with the same result)
The code is:
int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct) {
..........
if (!m_wndStatusBar.Create(this)) {
TRACE0("Failed to create status bar
");
[Code] ....
This code was placed within a program created by the MFC wizard that does nothing else. I absolutely do not "touch" the status bar after it is created here in CMainFrame::OnCreate().
Apparently the icon is "erased" after OnCreate() exits. Where, how? I have made HICON icon; a member of my CMainFrame class, with the same result.
Code:
Int** d = malloc( ROWS * sizeof(int*));
for (i = 0; i < ROWS; i++)
d[i] = malloc(COLS * sizeof(int));
fx(d);
My question is, in a function declaration, why do I not have to specify the number of columns. How is this different than when I pass a static 2D array to a function, in which I must declare the function parameter with the number of columns.
Code: void fx(int d[][COLS]);
VS.
Code: void fx(int **d);
I remember in C++, when a dynamic array is allocated, the size of this array is stored right before the array in memory. Therefore compiler knows exactly how long, when this array is deleted.
Do all compilers store the size this way? Is it a safe method to get the size of a dynamic array?
Here is a example code, it works fine on Visual Studio 2012.
#include <iostream>
using namespace std;
class dummy {
public:
dummy() {
cout<<"dummy created"<<endl;
[Code]...
