The first part of the exercise is to read the lines from a file placing each line into an array. I thought my code looked correct however nothing but garbage prints out. Here's my code.
#include <iostream>
#include <fstream>
#include <string>
[Code]...
I'm trying to read in lines for a file and storing it in an array. This is what I have so far. Am I allocating the memory correctly?
Code:
typedef struct {
/* declartion of variables */
} App
typedef struct {
[Code].....
How do I access the array content? I'm suppose to strtok the contents from the lines stored in the array and use it again.
i want to read text between two indices in the file using file i/o operations in c++. HOw can i do it? for example, here is the text file:
1:
..
..
2:
..
..
3:
..
..
4:
in this text file i need to print only the lines between 2: and 3:. How could this be done?
I am trying to read lines from a .txt file like this:
// "file.txt"
This is the first line.
This is the second line.
To do this, I tried using the following code:
int main() {
std::ifstream data;
data.open("file.txt");
[Code] ....
The output I want is:
This is the first line.
This is the second line.
However, all I am getting is:
This is the first line.
I can't quite see why this isn't working. I am decently familiar with file streams in C++, so I thought I would know what I was doing, but apparently not.
Program background: Ticket Sales Details You will sell tickets in advance and at the door. Prices for buying in advance and at the door will be given. Also, the total number of tickets sold in advance will be given. Each guest will have a unique number. If there are n tickets sold in advance, then these guests will be numbered 0 through n-1. As the event starts, requests to buy tickets at the door may be made and these guests will be numbered sequentially, starting at the lowest unassigned number. The maximum number of guests will be 1000. The first line of the file contains the following three values, separated by spaces: Cost of the presales tickets (in dollars), Cost of the tickets at the door (in dollars), and the number of presale tickets. The first two values will be positive real numbers to two decimal places and the last will be a positive integer.
The second line of the file will contain one positive integer representing the number of auction items followed by a positive real value to two decimal places (at most) representing the minimum bid increment, in dollars. The first value is guaranteed to be 1000 or less and the second will be in between 1 and 50, inclusive.
The third line of the file will contain all the prices of the auction items, in dollars, separated by spaces, in order. Thus, the first price is the price of item 0, the next price is the price of item 1, and so on. These values will be real numbers represented to up to 2 decimal places.
The fourth line of the file will contain the three following positive integers pertaining to the raffle: the number of raffle tickets available, the cost of a raffle ticket in dollars, and the number of raffle prizes. (It's strange to have raffle tickets that don't cost a whole number of dollars.)
The fifth line of the file will contain each of the values of the raffle items, in dollars, separated by spaces, in order. Thus, the first price is the price if item 0, the next price is the price of item 1, and so on. These values will be real numbers with upto 2 decimal places.
The sixth line of the file will contain ten positive integers representing the number of each of the drinks 0 through 9, in order, that are in stock.
The seventh line of the file will contain ten positive real numbers with upto 2 decimal places representing the price of each of the drinks 0 through 9, in order.
The eighth line of the file will contain a single positive integer, numEvents, representing the number of events that occur at the charity ball. These events are split into two groups: actions by guests at the ball and awards given (raffle, auction, person, totalrevenue). All of the actions precede all of the awards. You will produce exactly one line of output for each event described. Here are the formats of each event that could occur:
If a patron buys a ticket at the door, a command will be on a line by itself:
BUY TICKET k
where k is a positive integer indicating the number of tickets bought at the door. These guests will be numbered as previously mentioned. You are guaranteed that the total number of tickets bought, including presales, will not exceed 1000. This is what I have so far and I cannot figure out why it wont calculate the total revenue. I am not completely sure if it is even accessing the if statement in main.
Code:
#include <stdio.h> #include <stdlib.h>
#include <string.h>
#define N 1000
[Code].....
lets say this is our textfile
-----------------------------------
45(here is space)string and other shit is here
454(here is space)string and other shit is here
4121(here is space)string and other shit is here
77(here is space)string and other shit is here
45545(here is space)string and other shit is here
1122(here is space)string and other shit is here
-----------------------------------
how do i get exactly that number in every line start? and compare but i jus tneed to get them to variable so ?
how to read random lines from a text file using "C", without repeating same lines.
View 10 Replies View RelatedI have a file that I need to read in blocks. I need to read in n lines at a time, do some processing, and then read in the next block of n lines until the file is done. I know the size of the block, but not the number of lines in the file unless I check that first. Normally I would read in like,
Code:
// declarations
string new_input_line, input_file;
// create an input stream and open the input_file
ifstream input_file_istream;
input_file_istream.open( input_file.c_str() );
[Code] .....
// process through data_block
With this approach, I'm not sure how I would keep looping to read the next block until I hit the end of the file without knowing how many lines are in the input file. I could process the file to find that out, or get that number from bash and pass it it as an argument, but it seems like that shouldn't be necessary.
I could also read in and store the entire file as a vector of string and then process through it afterwords, but that would not be a very efficient use of memory.
Simple program to convert files to XML files. However I am trying to narrow down why my code is not working. I am reading a line that looks like "2001 Joe Dirt Los Angeles", then the next few lines are followed by text and the the fifth line looks like "---End of Description---".
So here is the file
2001 Joe Dirt Los Angeles
Home is where you make it
Best movie ever(but not really)
But seriously
---End of Description---
Here is example code to test the process
string line;
while(dataFile >> line) {
getline(dataFile, line);
cout << line << endl;
}
My returning output is
[space]Joe Dirt Los Angeles
[space]Home is where you make it
[space]Best movie ever(but not really)
[space]But seriously
My test code is skipping the date on the first line but replacing it with a space. Then it is skipping my fifth line which reads "---End of Description---". Now if I take the code out of the while loop and hard code in five lines of output (x5 getline(dataFile,line); cout << line << endl;) then my code works as expected. I get all of the information. Date and the fifth line.
It looks like when I am testing for the EOF it is also taking in the numeric value at the beginning of the first line. However, that does not explain why it is dropping that fifth line.
I know to read a strings into array and tables.. what is they are mixed up?? strings are just names ( 3 characters) and there are bunch of table.. the max size was set to 60
ex. text file
JES
DAN
JEN
.
.
.
01010101
10010101
RAM
JET
01010010
10100101
.... and so on
should i use a while loop?
i've been trying to write array into file and read them into the same program again, but the output is all wrong.
Code:
#include<stdio.h>
int main()
{
FILE *fp;
char name[3][7];
int x;
}
[code]....
This is what I am supposed to be doing with this problem: Read the integer values in the file "numbers.dat" and display
* them in reverse order (that is, display the last number in the
* file first, the second-to-last second and so on). Use an array to
* store the values. It is safe to assume that the file contains no
* more than 100 values.
I have gotten far enough to read the file and display as an array, but it is displaying vertically rather than horizontally. So it is displaying 10 and a 1 on the first line then the 0 on the second line. Before I can work the reverse part out, I need it to display each number as 10 line 1 -235 line 2 so on and so forth.
This is my code so far:
void display_array_reversed() {
ifstream fin ("numbers.dat");
if (!fin){
cerr << "Error opening file" << endl;
exit(1);
[Code] .....
So if I have a file that has a list of scores and the name of the student, how am I going to read the scores and names, and print to output? For example, the text file will look like:
83 75 89 90 75 67 John Doe
67 92 78 64 88 95 Jane Waters
76 65 87 70 97 76 Billy Bob
And they'll be printed like that too.
I made a 2D array for the scores and names, and was able to scan the scores into the scoreArray, but I am stuck for the names. Do I use fscanf, fgets, etc? And how do I use these for a char array?
insert Code:
int main {
int scoreArray[NUM_ROW][NUM_COLUMN];
char nameArray[NUM_ROW][SIZE];
...........opened file, etc.
[ for (row=0; row<2; row++)
{ if(row>0)
{printf("
[Code] ....
When I run this, I get the scores and names (somewhat) in a jumbled mess.....
My assignment is to read in from a .txt file two things: an integer and a string. After reading in these 2 items I have to put them into a 10x10 2D array so that both the number and the character can be manipulated by the user. Here are the contents of the text file:
Dr. J's Garden
0.21,B, 2.80,G, 4.96,B, 2.66,B, 4.48,B, 0.61,T, 0.40,B, 3.50,G, 3.63,B, 3.91,T,
2.33,T, 4.51,G, 1.15,G, 4.95,T, 2.76,T, 4.51,T, 2.54,G, 4.04,T, 2.38,B, 0.62,B,
4.54,G, 3.38,T, 1.57,T, 3.92,T, 3.03,B, 4.72,G, 0.23,B, 4.02,G, 4.69,G, 0.66,G,
1.34,T, 2.21,G, 2.48,G, 4.85,T, 3.25,G, 3.55,G, 4.78,B, 0.81,G, 0.74,G, 2.55,G,
3.35,G, 4.52,G, 4.81,G, 2.67,G, 4.97,B, 0.87,G, 1.28,G, 4.58,B, 1.91,B, 3.69,B,
3.02,T, 3.15,T, 1.08,T, 4.68,G, 1.10,B, 3.17,G, 1.97,T, 0.99,G, 4.50,T, 3.87,T,
3.36,G, 1.60,T, 3.73,G, 2.14,B, 3.68,B, 2.44,G, 3.10,G, 4.54,B, 0.25,B, 0.25,G,
1.79,B, 3.02,G, 2.21,T, 0.22,G, 3.67,B, 4.46,G, 2.14,G, 2.31,G, 0.80,T, 3.83,B,
1.56,B, 1.41,T, 0.80,G, 1.27,T, 0.08,B, 1.20,G, 2.88,B, 2.78,T, 3.30,B, 1.75,B,
2.60,G, 4.72,T, 4.55,T, 0.89,B, 0.52,B, 2.06,T, 0.28,G, 4.36,T, 4.41,G, 0.36,B,
One number and one character need to be assigned to each element of the array. I know exactly how to fill a 2D array when it's just numbers, but the characters and the commas are giving me a lot of trouble.
i'm reading a file which has 20 rows and random number of columns, i want to put them in array/vector which i did but the problem is that array is filling a cell with a garbage value at location where i don't have a value in the data file.
suppose i have data file like following (there is tab between each column and each row has different number of columns)
Code:
20 30 10
22 10 9 3 40
60 4
30 200 90
33 320 22
here is my code
Code:
#include <vector>
#include <iostream>
#include <fstream>
[Code]....
Code:
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
struct inventory
[Code]...
This is my program output Enter the file name : "filename".txt ..... (Nothing shows up)
why when I print out "array[2]" nothing prints? It just prints blank space. My file definitely has text in it, but when I try to assign "text" into the array of pointers it won't show any text. I know fgets() appends a newline at the end of the string, not sure if that has anything to do with it, but I've tried printing everything that should be in "array" with a for loop and I get nothing.
Code:
#include <stdio.h>
#define FILEPATH "/home/user/Desktop/text"
int main(){
FILE *myFile = fopen(FILEPATH, "r");
if(myFile == NULL) return 0;
char text[100];
char *array[100];
int idx = 0;
while(fgets(text, 100, myFile)){
array[idx++] = text;
}
puts(array[2]);
}
I have to write a program that reads from a text file, which contains a list of stock hourly prices and the company names. Something like this:
78.52 82.56 75.10 71.97 Water Company
22.40 25.68 21.37 22.96 Mega Shipping Inc
There's suppose to one array of companies, where each company will be kept in a structure that contains: a pointer for the name, an array of the prices, and the average price for the day. The structures will be kept in an array of structures.
My question is, how do I read the data from the file and put the data from each line into the next structure in the array of structures? I read the numbers in fine. I just use:
Code: fscanf(fp, "%f", &companyAry[i].hourlyPrices[j]);
But my program crashes when I try to read the name.
Code: fscanf(fp, "%[^]", &companyAry[i].companyName);
I'm thinking it has something to do with the fact the companyName is a pointer.
My structure looks like this:
Code:
typedef struct {
char *companyName;
float hourlyPrices[NUM_PRICES];
float avgPrice;
}
COMPANY;
My problem is that I need to take a csv or excel file with tens of thousands of datapoints, write all points in a section of column to an array, perform calculations on them, and then write it back into another column.
I've been looking all over the internet for ways to do this easily. So far I have not found anything that I can follow and implement.Some codes have been slightly useful, but they aren't commented in a way I can understand. How to write code to take, for instance, lines from column b between 500-1000, write them to an array, and write another array 500 characters in column c. If that code could be commented, I have tried a few different techniques (counting commas), but haven't gotten anything to work.
I'm having issues reading to a 2d array from a file. When I try to read the data from my file into my matrix variable it simply doesn't read anything and leaves the variable unmodified. I've tried just reading the first piece of data in the main function and it doesn't work there either. I'm really perplexed at this point since I've never had an issue reading from a file before. Here's my relevant code:
Code:
int main(int argc, char** argv) {
double matrix[MINSIZE][MINSIZE]={0}, vectors[MAXSIZE][MINSIZE], ans[MAXSIZE][MINSIZE];
FILE * inFile;
inFile = fopen(FILENAME,"r");
if(inFile==NULL){
printf("File does not exist.
[Code] .....
Is something like this possible and if not how can I make this work?
fscanf(in, "%d %d %d", &i, &x, &arr[i+x]);
I am working in Eclipse, and it keeps giving me this error that I do not understand. In the fillTable function, "is >> kP[i]" Eclipse says: no match for 'operator>>' in 'is >> *(((TranslationTable<int, std::string>*)this)->TranslationTable<int, std::string>::kP + (+(((unsigned int)i) * 8u)))'.
#ifndef TRANSLATIONTABLE_H_
#define TRANSLATIONTABLE_H_
#include "KeyValuePair.h"
#include <iostream>
#include <cstdlib>
[Code]....
Reading in a maze into a 2D array. The first two reads will give me the dimension of the maze(ex. m x n maze). So in order to create the 2D array i need the first two reads. Then after it is created it will read the rest of the data which are 1s and 0s. I have to create a program that will solve the maze but i cant test my movement code if i cant read in the data first. the entire program compiles but to test if i read the file i have a function to print it. But it says "There are: 0 rows and 0 columns " so it didn't read anything since rCount and cCount are initialized to 0. and basically the maze has nothing in it.
Code:
#include <iostream>
#include <fstream>
#include <stack>
#include <cstdlib>
#include "position.h"
[Code] .....
I have a text file with scores and names.
I have to read the score into an array and the names into an arrays also
27,Tom Jefferson
23,Ozzie Osborne
18,Wilt Chamberlain
15,Marie Antoinette
I've gotten the score to display correctly, but i cant get the full names. My function only reads the first names
I started making something for my class and the thing im getting stuck with is this function:
void ucitajOdgovore(string asocijacija[21]){
int brojac=0;
ifstream fajl;
string putanja;
/*srand(time(NULL)); int random=(rand() %5) +1;
switch(random){
[Code] ....
In the main, i pass real string array "asocijacije" in function which i use in it, and when i use it after this fun. i get an empty array. Its like it didnt happend and i cant see where i went wrong.
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
struct inventory {
int barcode;
char description[512];
[Code] ....
This is my text file
20123451
Sugar packet (1 kg)
2.50
560
21347652
Milo 3-in-1
12.50
200
20123453
Salt (1kg)
4.50
270
21347654
Nescafe 3-in-1
12.50
400
20123455
Tamatoes
4.00
100
21347656
Cucumbers
4.00
280
This is my program output
Enter the file name : "filename".txt
..... (Nothing shows up)