How 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?
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 am facing a problem which i could not obtain the total numbers which is greater than the average value. For example:
#include <iostream>
using namespace std;
int main (){
int size , count;
double no, max, min ,total, sum , average;
[Code] ....
In this case im able to compute the average of the numbers but when it comes to capture the total of numbers which is greater than the average value, how to compile the code , because the average number is only been compute once all the value capture by the input of user is sum up.
Any good function that get the length of an integer in C++
I do know of str.length(), however i want something similar for integers
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.
parallel post: [URL]...
i have seen many example for to get the data from wmi using c++. will it work on turbo c++ or vc++. if it is written in vc++ means could we develop the same concept using c++?
Note: the link that i have seen the example [url="hi, i have seen many example for to get the data from wmi using c++. will it work on turbo c++ or vc++. if it is written in vc++ means could we develop the same concept using c++? Note: the link that i have seen the example[URL]
I would like to convert the string without losing the decimal part and obtaining the same accuracy... This is my code:
#include "stdafx.h"
#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
using namespace std;
int _tmain(int argc, char* argv[]){
string param = "1.65";
double L3;
L3=atof(param.c_str());
}
If I use atoi L3 = 1.00000; and if I use atof L3 = 1.6499999999;
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 writing a raytracer, and currently I'm working on creating a bounding volume hierarchy to accelerate the process. To do this, I am first creating a vector that holds each of the objects in the scene, and passing this vector to the constructor for my BVH.
Code:
//in header
BVH_Node* bvh;
//in main raytrace function
[Code] .....
I am testing a scene that has only 2 objects, and so it goes to the size == 2 check. The first time it hits makeLeaf(), I segfault. I've used both gdb and valgrind, and of course it's a memory mapping error. gdb's backtrace tells me that the length of the vector I've passed in is -805305610 and the capacity is -21, and that it is inside my makeLeaf() function that the error occurs.
Here's the function:
Code:
BVH_Node* BVH_Node::makeLeaf(GeomObj* v){
BVH_Node* node;
node->obj = v;
node->isObj = true;
return node;
}
The segfault happens at
Code: node->obj = v;
If I run my raytracer without a BVH, the objList works perfectly.
We have to write a function named fibonacci that takes an int indicating the length of the series and then store it in an array of size 20 printing the sequence from largest to smallest. Here is the small bit i have so far:
#include <iostream>
#include <iomanip>
using namespace std;
void Fibonacci( int );
int main( ) {
[Code] ....
I just need something to get me on the right track.
I am trying to use fscanf to obtain a set of 14 or so strings per line, in a line where there are around 80 or so different sets of strings. I only need the first 14 and whenever I call scan f it starts at column 209 as opposed to column 1 where it should. Here's a sample of the code:
FILE *d;
d=fopen("t.dat","rb");
where a, n are all strings.
fscanf(d,"%s %s %s %s %s %s %s %s %s %s %s %s %s %s",&a,&b,&c,..(etc)..,&n);
A sample of the Input file looks like this:
USB270.15385-29.63146 270.153847 -29.631455 2.966699e+03 -9.99 1.300391e+03 -9.99 -9.99 A-A-- 6.787463e+01 -9.99 1.555773e+02 -9.99 -9.99 10100 | ----- ------ ------ ------ | 0.373 13.554 12.928 12.670 AAA | ----- -------- - -------- - -------- - -------- - | --- ---------- - ---------- - --------- - --------- - --------- - ---------- -
I was just reviewing some code, and my eye fell on a bit of regex that's intended to parse a date/time stamp into a date and time.
The timestamp uses shorted month names. The regex had all the possible month names to match the entire pattern. If it does, it went through a 2Nd loop to convert the month name into a 1 to 12 numeric value...
This made me wonder, since the regex is already doing the work to verify the alternation, can't it at the same time tell me which of the possible alternations it matched and use that to calculate the numeric value. So basically
Code:
std::regex reMonth("Some more regex stuff here (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec).");
CString strTest("Some more regex stuff here Aug.");
std::cmatch res;
if (std::regex_match(strTest.GetString(), res, reMonth)) {
//int iMonthNum = res[1].something(); // some code here that returns 8 for Aug.
}
Or is there really no other way out than doing a 2nd level verification to figure out the actual month number. (The real regex is a bit more complex than this).
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 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.
View 5 Replies View RelatedI'm using SQLBulkOperations to insert rows in bulk. I'm using SQLBindCol to bind the columns before SQLBulkOperations().
But how do I obtain the Identities? The bound buffer for the Identity column does not get filled after SQLBulkOperations()
At first I tried to use Bookmarks (column 0), but it seems that that is some other value (thought it would be filled with identities). But now I thought it must be that the bound buffer for the Identity column itself must be updated, but it's not happening. Maybe I need to do something extra?
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.
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 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 have to obtain a check number from a datafile and then also get company information also from a datafile.
So my first question is about the:
Code:
char outputFilename[]= "out.list"
Is this the name of the output file I'm going to write to? And also the file has to be created before being used...is that line of code creating the file or do i have to create it in notepad?
Code:
FILE *ifp, *ofp;
char *mode = "r";
char outputFilename[] = "out.list";
ifp = fopen("in.list", mode);
if (ifp == NULL) {
fprintf(stderr, "Can't open input file in.list!
[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...
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