How can I read this file in to my struct?
12345Joe Lim KH879.00
12233Kay Suet Yee35.98
23781Leong Jing Yang 10.00
67543Woon Tian Yi500.50
struct master {
unsigned short int IDnum;
[code]....
not working
How can a mulitline string be read line by line
ex: str = "PERIOD="week"
DAY="day"
TIME="time"";
Is there any way to make a switch in C. That I can choose between different data types? For example, at the moment I need to know how to read one parameter. It must recognize if it is a boolean or uint32.
View 4 Replies View RelatedI'm reading strings one after another and trying to split it using strtok_r. This doesnot seem to be working
I have a .gz file from which I'm reading the data into the buffer in chunks.
The below code works fine only for the first chunk on data. Later it just breaks out.
while(1) {
char buffer[SIZE];
int bytes_read = gzread (f, buffer, SIZE - 1);
[Code] .....
I have an external file with one column of data. If I have a counter value let say counter =1, and counter++ and so on. How I can write such a c++ code that if the value of counter and value from the external file are same then generate an action let say cout both values i.e. value of counter and value from external file.
for more information, here is an example:
data in file(in one column): 2 6 8 9 10...
value of counter : 1 2 3 4 5 6 7 8 9...
then cout values only if value of counter and value from the file is same.
Here is my code so far, but it does not seem to work;
#include<iostream>
#include<fstream>
using namespace std;
int main() {
const int SIZE = 10; //Size declaration of array
int hours[SIZE]; //Array declaration
[Code]...
How to read a line with maximum of 8 bytes from a line in a file.
Let say line has 10248 bytes in one single line and same repeats for remaining lines in the file.
I need to read the first 8 bytes of a line and go on read the last 2 bytes of the line and repeat the till end of file.
#include<iostream.h>
#include<conio.h>
main()
[Code]....
I tried to make the output look like this --> ENTER YOUR NAME:Victor Collin ENTER YOUR COURSE:BSComSci
but everytime I entered my name the course went to the next line.How to make the output in the same?
struct InnerNode {
int key_count;
vector<type> keys[M];
int child_count;
union {
[Code] ....
In c++, is there any way to specify a type for a struct local dynamically? My plan is to implement a B+ Tree, but I want this to work with different data types. Could I do this using a constructor?
I'm trying to union eleven tables to call out data. Parent table is 'Events', child tables are 'SR1Laptimes', 'SR2Laptimes' and so on (there are ten SR... tables). Primary key in all tables is EventName. Parent/Child relationship is Events.EventName/SR1Laptimes.EventName etc All tables that start with SR have the same Schema. I'm trying to call out MIN(Q1) across all table but first need to Union them I believe. Here is my code.
myCommand.CommandText = "SELECT MIN(Q1), MIN(Q2), MIN(Q3), MIN(Q4), MIN(LaptimesMinutes), MIN(LaptimesSeconds) FROM (SELECT * FROM Events UNION ALL SELECT * FROM SR1Laptimes UNION ALL SELECT * FROM SR2Laptimes) WHERE (Events.Track = @track) AND (Events.Number = @number) AND (Events.Rider = @rider)";
myCommand.Parameters.AddWithValue("@track", analysisTrackComboBox.Text);
myCommand.Parameters.AddWithValue("@number", analysisNumberComboBox.Text);
myCommand.Parameters.AddWithValue("@rider", analysisRiderComboBox.Text);
I'm using fgets which will read a single line at a time, but unlike fgets I don't want it to return the new line char ( ) ?I want to be able to use printf to display the lines next to each other.
View 7 Replies View RelatedI have a text file (test.txt) with the following data:
01,05,25,20130728
01,06,25,20130728
01,07,25,20130728
01,08,25,20130728
01,05,25,20130728
01,05,25,20130728
01,05,45,20130728
01,05,65,20130728
01,05,85,20130728
01,05,35,20130728
01,05,25,20130728
01,05,35,20130728
I want to read this to one string called line. So far I have this code:
string line;
ifstream myfile ("/home/Test.txt");
if (myfile.is_open()) {
while (myfile.good()) {
getline (myfile, line);
for (int a = 0; a <= 335; a++) {
cout <<line.at(a);
} }
myfile.close();
}
so far its only printing the first line and then throwing an instance of 'std::out_of_range'
I need to read a text file which has various lines containing integers. I need to write those integers separately in a vector. Example, the first line of the text file contains 3 9 8 7 6 so vector[4]=3, vector[3]=9, vector[2]=8 and so on. Next read the second line 4 1 2 3 4 5 and write to another vector vector[5]=4, vector[4]=1...
I tried the code below but it will write from the second line, the whole line in one vector index.
int str; // Temp string to
cout << "Read from a file!" << endl;
ifstream fin("functions.txt"); // Open it up!
string line;
// read line count from file; assuming it's the first line
getline( fin, line );
[Code]...
I have a SSD and I am trying to use it to simulate my program I/O performance, however, IOPS calculated from my program is much much faster than IOMeter.
My SSD is PLEXTOR PX-128M3S, by IOMeter, its max 512B random read IOPS is around 94k (queue depth is 32). However my program (32 windows threads) can reach around 500k 512B IOPS, around 5 times of IOMeter!!! I did data validation but didn't find any error in data fetching. It's because my data fetching in order?
I paste my code belwo (it mainly fetch 512B from file and release it; I did use 4bytes (an int) to validate program logic and didn't find problem).
#include <stdio.h>
#include <Windows.h>
/*
** Purpose: Verify file random read IOPS in comparison with IOMeter
**/
//Global variables
long completeIOs = 0;
long completeBytes = 0;
int threadCount = 32;
unsigned long long length = 1073741824; //4G test file
[Code] ....
I am reading my file (20GB) line by line using boost like this
PHP Code:
boost::interprocess::file_mapping* fm = new boost::interprocess::file_mapping("E:Mountain.7z", boost::interprocess::read_only);
boost::interprocess::mapped_region* mr = new boost::interprocess::mapped_region(*fm, boost::interprocess::read_only);
char* bytes = static_cast<char*>(mr->get_address());
An exception is thrown in the second line while allocating memory for mr.
I use boost because it can also work in Mac which my code will be ported to.
int* count;
count = new int(1); // what???
Is this on the heap?? do i have to delete it now?
So is 'new' on a primitive data type just a way for me to allocate primitive data types (int, char, etc.) on the heap instead of the stack?
And, out of curiosity, can you do that in Java?
How to convert these data types? i have an array of bytes in unsigned char[] array, and need to convert to const void* pointer.
View 3 Replies View RelatedHow do you create an object (like in the title) something more simple than a struct? I wanna know that cuz I'm writing a function that could return a boolean and an integer at the same time.
View 2 Replies View RelatedWhat are the possible problems if I declare a bunch of data types and never use them? Do they take up a lot of memory? Will they slow run time? If it is an array do I have to delete it at the end of the program? What if the array is defined inside a class and never used? Do I still have to delete it?
i.e.
Code: class declarearrays{
public:
double **darray;
double **darray2;
void function1();//function that initializes darray
void function2();//function that initializes darray2 with different parameters, may not be used.
};
I am trying to create a generic map container which shell contain data of different datatypes. I already found a solution in this forum here:
[URL]...
Introducing a container with a Base Class as content type and inserting objectes of Derived Class types from that Base Class suites my implementation very well. But it is not really working. I implemented it this way:
class MyType {
public:
MyType() {}
virtual ~MyType() {}
}; template <class PT> class ParseType : public MyType
[Code]...
Then I insert one element.
// index being an object of type Parser<string>
ParseType<string>* test = new ParseType<string>( index );
// and index.val(0) = "-n"
iMap.insert( pair< string, MyType* >( index.id(0), test ) );
Now I think I should be able to call
const string key("-n");
iMap.at(key)->content->val(n);
Or
iMap.at(key)->get_val(n);
But neither one compiles with the error that "class MyType" (as the map container is pointing to a MyClass object) has no member/member function "content"/"get_val".
I also tried introducing member and member function "content" and "get_val" in "class MyType", which I thought should be hidden while constructing ParseType<string>. This would compile but it does not call the member "content or member function "get_val" from class ParseType.
A second try was to remove templatization of "class ParseType" and introduce a specific, let's say, "class ParseString" for objects of type Parser<string>. But the problems remain the same either the compiler complains due to missing member/member function or retreiving the map content will not call the derived class member/member function.
I'm fairly new to C++ programming. I wanted to accept a datatype as an input. I've seen something similar while working with the <queue> library.
When defining a new object of queue
For example:
queue<int> Queue;
How is <int> handled ??
Basically I do not want to use a menu, instead just accept either an float or a single character. Then send the data to the appropriate spot based on the user input. I have been unable to convert the char to a float, and even if I did the char would probably only accept the first digit, say user enters '15' it would only read the '1'. I've tried strings instead of char but then unable to use the isalpha function. Do I need a char[] and then iterate through to get the numeric data? Then how do i make '1' and '5' become 15. There is probably a solution. I've also tried to use a loop waiting for the correct data while(!(cin >> letter)) which works but how do I get out if the user enters number.
#include <iostream>
#include <cctype>
#include <string>
#include <cstdlib>
using namespace std;
[code].....
I am doing a programming assignment. This program asks you to collect statistics on precipitation and temperatures from the four quarters of a year and print the calculated results. It is an exercise in using enumerated types and arrays. The measurements are entered at the end of every quarter.
Major variables (there are other variables) in the program:
Variable called: month of type Summary_Month (the enumerated type)
Arrays of integers called: low_temp, high_temp, precip
Array of doubles called: avg_temp
You will ask the user to enter the precipitation, low temperature and high temperature for each quarter. As you gather this data, you will calculate the average temperature (using avg_temp) for each quarter by averaging the low and high temperature for that quarter.
After you gather the information you will calculate and output : Total Precipitation for Year, Average Quarterly Precipitation, Average Quarterly Temperature, Highest Temperature for any quarter, Lowest Temperature for any quarter.
I am not getting the right output for average precipitation and temperature and I am not sure how to determine the highest and lowest temperature.
# include <iostream>
# include <iomanip>
using namespace std;
enum Quarters { March, June, September, December};
int main() {
const int NUM_QUARTERS = 4;
[Code] ....
how to correctly use pointers within relation to function parameters and main source file.
I noticed that char types, for example char myVariable[50]; which is an array, does not seem to require a pointer as if it already has one built in? as opposed to char *myVariable; which seems to need one - i assume this is because char has different ways to store memory in relation to pointers, because of there being multiple ways to store a string, and memory allocation as a part of that. - i stared C a few weeks ago and feel that it is difficult to progress without nailing down pointers. Also address operators provide confusion for me and written tutorials are not so clear because there are different ways to use these operators.
What is the maximum and minimum of int, long int, long long int, double, float, and anything bigger than that? And also how to calculate this?
View 4 Replies View RelatedIn my platform (Windows 7 Ultimate 64 bits with Service Pack 1 over a compatible PC with a AMD x86 microprocessor), the next sample C++ code,
#include <iostream>
#include <limits>
using std::cout;
using std::endl;
using std::hex;
using std::showbase;
using std::numeric_limits;
[Code] ....
Compiled with Microsoft Visual C++ 2010 Express, prints this output:
ui = 0xffffffff
ull = 0xffffffff
sll = 0xffffffff
si = 0xffffffff
ull = 0xffffffffffffffff
sll = 0xffffffffffffffff
So, in my platform, conversion from an unsigend integer primitive data type to any bigger integer primitive data type never extends the most significant bit of the former integer and conversion from an signed integer primitive data type to any bigger integer primitive data type always extends the most significant bit of the former integer. This is convenient to mantain the same value when converting between integer primitive data types of the same signedness (i.e, signed integers or unsigned integers).
How to properly read data from a .txt file.
If I have data stored in a .txt file, which is formatted/stored like this:
Code:
Apples and Strawberrys
10
Cherrys
12
Pears
16
Grapes, Melons, and Peaches
20
I know that if I read/extract, and print the data like this;
Code:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main() {
ifstream dataFile("test.txt");
string textData;
[Code] ....
Each line of data is stored in the string "textData" and printed to the screen, exactly as it was stored in the .txt file. So, all is clear to me up to that point.
But, what if I wanted to store each line of text in the string "textData", and store the numbers/integers into a separate variable called "numberData"? How would I retrieve and store the numbers (in the above example .txt file, every 2nd line) separately from the text?
For now, to keep things simple, let's assume that the data in the .txt file is stored/formatted as in my example (1 line of text, 1 line containing a number/integer, ...repeat) so, there is no need to test if the retrieved data is actually text or an integer, before it is stored in the appropriate variable type.