我想要尝试做的是解析包含一个人的名字、姓氏和体重的 CSV 以及结构数组中的这些数据。到目前为止，这是我的代码。我能够解析并打印出 CSV 的值，但我不太确定如何将这些值存储到结构数组中。我希望能够从 person.c 访问 csv 的值，但实际上是从 vector.c 读取该值，这意味着我必须在 vector.c 中从 person.c 调用函数 readCSV() 。你们有人能帮我吗？
//vector.h
#ifndef VECTOR_H_
#define VECTOR_H_
#include "person.h"
typedef struct
{
Person *personArray;
int sizeArray;
int count;
}Vector;
//person.h
#ifndef PERSON_H_
#define PERSON_H_
typedef struct
{
const char *firstName, *lastName;
double weight;
}Person;
//vector.c
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include "vector.h"
void readPerson(Vector *v)
{
readCSV(v->personArray);
}
//person.c
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include "person.h"
void initialize(Vector *v)
{
v->sizeArray = 10;
v->count = 0;
v->personArray = (City*) malloc(v->sizeArray*sizeof(City));
}
void readCSV(Person* person)
{
FILE * fp;
char line[1024];
int i = 0;
fp = fopen("mycsvfile.csv","r");
while(fgets(line,sizeof(line),fp))
{
person->firstName = strtok(line,",");
person->lastName = strtok(NULL,",");
person->weight = atof(strtok(NULL,","));
printf("%s %s %f\n",person->firstName, person->lastName, person->weight);
}
fclose(fp);
}
//main.c
#include<stdio.h>
#include<stdlib.h>
#include "vector.h"
int main()
{
Vector people;
initialize(&people);
readPerson(&people);
return 0;
}
如下：
int readCSV(Person* person, FILE *fp){
int state;
char line[1024];
if(state = fgets(line,sizeof(line), fp)){
person->firstName = strdup(strtok(line,","));
person->lastName = strdup(strtok(NULL,","));
person->weight = atof(strtok(NULL,"\n"));
printf("%s %s %f\n", person->firstName, person->lastName, person->weight);
}
return !!state;
}
void readPerson(Vector *v){
//if(!v && !v->personArray)
FILE *fp;
int count = 0;
if(NULL != (fp = fopen("mycsvfile.csv","r"))){
while(readCSV(&v->personArray[count], fp)){
if(++count == v->sizeArray){
//expand array or stop reading
}
}
v->count = count;
fclose(fp);
}
}
您的代码有两个主要问题：
打印在您的代码中起作用，因为您在调用 fgets() 之前打印了解析的数据。但问题 2 使您无法分离解析和打印。
此代码修复了这两个问题，并将打印移动到不同的功能，进行最少的编辑。我已将 person.c 重命名为 vector.c，因为其中的函数处理整个向量而不是单个人。
//person.h
#ifndef PERSON_H_
#define PERSON_H_
typedef struct
{
const char *firstName, *lastName;
double weight;
}Person;
#endif
//vector.h
#ifndef VECTOR_H_
#define VECTOR_H_
#include "person.h"
typedef struct
{
Person *personArray;
int sizeArray;
int count;
}Vector;
extern void readCSV(Vector* people);
extern void printCSV(Vector* people);
#endif
//vector.c
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include "vector.h"
void initialize(Vector *v)
{
v->sizeArray = 10;
v->count = 0;
v->personArray = (Person*) malloc(v->sizeArray*sizeof(Person));
}
void readCSV(Vector* people)
{
FILE * fp;
char line[1024];
int index = 0;
fp = fopen("mycsvfile.csv","r");
while(fgets(line,sizeof(line),fp))
{
people->personArray[index].firstName = strdup(strtok(line,","));
people->personArray[index].lastName = strdup(strtok(NULL,","));
people->personArray[index].weight = atof(strtok(NULL,","));
++index;
}
people->count = index;
fclose(fp);
}
void printCSV(Vector* people)
{
int i;
for( i=0; i<people->count; ++i )
{
printf("%s %s %f\n",
people->personArray[i].firstName,
people->personArray[i].lastName,
people->personArray[i].weight);
}
}
//main.c
#include<stdio.h>
#include<stdlib.h>
#include "vector.h"
int main()
{
Vector people;
initialize(&people);
readCSV(&people);
printCSV(&people);
return 0;
}
该代码有效，应该可以让您继续您的工作或任务。但为了成为符合生产状态的高质量代码，还有许多问题需要解决：
#include <iostream>
#include <string>
#include <fstream>
#include <iomanip>
#include <limits>
#include <algorithm>
using namespace std;
const int MAX_TOPPINGS = 2;
const int MAX_DONUTS = 50;
struct donutType {
string name;
bool type;
double price;
string filling;
string toppings[MAX_TOPPINGS];
};
ifstream getFileStream(string);
int getDonuts(ifstream&, donutType[]);
bool continueMenu(string);
void sortByPrice(donutType[], int);
int searchByName(const donutType[], int, string);
void removeDonutFromList(donutType[], int&, int);
int getCheapestDonut(const donutType[], int);
void soldDonut(donutType, donutType[], int&);
void outputSoldDonuts(ofstream&, const donutType[], int);
void displayAvailableDonuts(const donutType[], int);
string allCaps(string);
/**
* The main function to manage the donut ordering program.
*
* @return The exit status of the program.
*/
int main() {
ifstream infile;
ofstream outfile("sold.csv");
string filename;
string request;
donutType donuts[MAX_DONUTS];
donutType soldDonuts[MAX_DONUTS];
int amtDonuts = 0;
int amtSold = 0;
double total = 0;
cout << fixed << setprecision(2);
// gets step 1 the input stream
infile = getFileStream("Enter a donut file: ");
// step 2 get total donuts
amtDonuts = getDonuts(infile, donuts);
// step 3 print to console
cout << "Welcome to Hank's Donut World!\n\n";
while (true) {
// step 4 print the available donuts to console
displayAvailableDonuts(donuts, amtDonuts);
//step 5 ask for user input
string nameEnteredByUser;
cout << "Enter donut name or cheapest: ";
getline(cin, nameEnteredByUser);
// step 6 check the user input choice and call function accordingly
int donutIndex;
transform(nameEnteredByUser.begin(), nameEnteredByUser.end(),
nameEnteredByUser.begin(), ::tolower);
if (nameEnteredByUser.compare("cheapest") == 0)
donutIndex = getCheapestDonut(donuts, amtDonuts);
else
donutIndex = searchByName(donuts, amtDonuts, nameEnteredByUser);
// step 7 check if the search results was empty
if (donutIndex == -1) {
cout << "Donut not found!\n";
continue;
}
// step 8 print the selection to console
cout << "You selected " << donuts[donutIndex].name
<< ".\nExcellent choice!\n";
// Step 9 inserting the sold donut into solddonuts array
total += donuts[donutIndex].price;
soldDonuts[amtSold] = donuts[donutIndex];
amtSold++;
// Step 10 removing the donut from donuts array
removeDonutFromList(donuts, amtDonuts, donutIndex);
// Step 11 choice to continue with more purchase
bool complete = continueMenu("Will this complete your order? ");
if (!complete) {
if (amtDonuts > 0)
continue; // go to Step 4
else
break; // End the program if there are no available donuts left
}
// Step 13 sort the donuts sold by price using bubble sort
sortByPrice(soldDonuts, amtSold);
// Step 14
if (outfile.is_open()) {
outfile << "Sold," << fixed << setprecision(2) << total << "\n";
outputSoldDonuts(outfile, soldDonuts, amtSold);
} else {
cerr << "Error opening output file.\n";
}
break; // End the program
}
return 0;
}
/**
* Retrieves an input file stream for a given filename after prompting the user.
*
* @param msg The message to prompt the user for the filename.
* @return An ifstream object for the specified filename.
*/
ifstream getFileStream(string msg) {
ifstream fileStream;
string fileName;
while (true) {
// Prompt user for a filename
cout << msg;
getline(cin, fileName);
// Open the file stream
fileStream.open(fileName);
// Check if the file stream is open
if (fileStream.is_open()) {
break;
} else {
fileStream.clear(); // Clear any error flags
cin.ignore(numeric_limits<streamsize>::max(), '\n'); // Clear input buffer
}
}
return fileStream;
}
/**
* Reads donut data from an input file stream into a struct array of donutType.
*
* @param infile An input file stream containing donut data.
* @param donuts An array of donutType to store the read data.
* @return The number of donuts read from the file.
*/
int getDonuts(ifstream &infile, donutType donuts[]) {
const int MAX_RECORDS = 50;
size_t MAX_CHARS = 100;
char line[MAX_CHARS];
int count = 0;
// Read and ignore the header line
infile.getline(line, MAX_CHARS);
// Read the CSV file line by line
while (!infile.fail() && count < MAX_RECORDS) {
// Read the entire line into 'line'
infile.getline(line, MAX_CHARS);
// Create a strings to parse the line
string lineString(line);
if(lineString.size() < 2)
break;
// Tokenize the line based on commas
size_t start = 0;
size_t end = lineString.find(',');
// Read name
donuts[count].name = lineString.substr(0, end);
//add plus one to skip the comma
lineString = lineString.substr(end+1);
// Read type
end = lineString.find(',');
donuts[count].type = (lineString.substr(0, end) == "Cake");
lineString = lineString.substr(end+1);
// Read filling
end = lineString.find(',');
donuts[count].filling = lineString.substr(0, end);
lineString = lineString.substr(end+1);
// Read toppings
end = lineString.find(',');
donuts[count].toppings[0] = lineString.substr(0, end);
lineString = lineString.substr(end+1);
end = lineString.find(',') ;
donuts[count].toppings[1] = lineString.substr(0, end);
lineString = lineString.substr(end+1);
// Read price
donuts[count].price = stod(lineString);
count++;
}
return count;
}
/**
* Displays a prompt and waits for user input to continue or exit.
*
* @param prompt The message to display as a prompt.
* @return True if the user chooses to continue, false if the user chooses to exit.
*/
bool continueMenu(string prompt) {
string input;
while (true) {
cout << prompt;
getline(cin, input);
// Convert the input to lowercase for case-insensitive comparison
transform(input.begin(), input.end(), input.begin(), ::tolower);
if (input == "no")
return false;
else if (input == "yes")
return true;
else
cerr << "Invalid input. Please enter 'Yes' or 'No' (case insensitive).\n";
}
}
/**
* Sorts an array of donuts based on their prices in ascending order using bubble sort.
*
* @param donuts An array of donuts to be sorted.
* @param amtDonuts The number of donuts in the array.
*/
void sortByPrice(donutType donuts[], int amtDonuts) {
for (int i = 0; i < amtDonuts - 1; ++i) {
for (int j = 0; j < amtDonuts - i - 1; ++j) {
// Compare prices and swap if needed
if (donuts[j].price > donuts[j + 1].price) {
// Swap
donutType temp = donuts[j];
donuts[j] = donuts[j + 1];
donuts[j + 1] = temp;
}
}
}
}
/**
* Searches for a donut by name in an array of donuts.
*
* @param donuts An array of donuts to be searched.
* @param amtDonuts The number of donuts in the array.
* @param name The name of the donut to be searched.
* @return The index of the found donut if present, otherwise -1.
*/
int searchByName(const donutType donuts[], int amtDonuts, string name) {
transform(name.begin(), name.end(), name.begin(), ::tolower);
for (int i = 0; i < amtDonuts; ++i) {
string donutName = donuts[i].name;
transform(donutName.begin(), donutName.end(), donutName.begin(),
::tolower);
if (donutName.compare(name) == 0)
return i; // Return the index if the name is found
}
return -1; // Return -1 if the name is not found
}
/**
* Finds the index of the cheapest donut in an array of donuts.
*
* @param donuts An array of donuts to be searched.
* @param amtDonuts The number of donuts in the array.
* @return The index of the cheapest donut if the array is not empty, otherwise -1.
*/
int getCheapestDonut(const donutType donuts[], int amtDonuts) {
if (amtDonuts <= 0)
return -1; // Return -1 if the array is empty
// Initialize to maximum possible value
double minPrice = donuts[0].price;
// Index of the cheapest donut
int minIndex = 0;
for (int i = 1; i < amtDonuts; ++i) {
if (donuts[i].price < minPrice) {
minPrice = donuts[i].price;
minIndex = i;
}
}
return minIndex;
}
/**
* Converts a given string to uppercase.
*
* @param s The input string to be converted to uppercase.
* @return The uppercase version of the input string.
*/
string allCaps(string s) {
string upper = s;
for (char &c : upper)
c = toupper(static_cast<unsigned char>(c));
return upper;
}
/**
* Removes a donut from the list based on the provided index.
*
* @param donuts The array of donuts.
* @param amtDonuts The current number of donuts in the array.
* @param removeIndex The index of the donut to be removed.
*/
void removeDonutFromList(donutType donuts[], int &amtDonuts, int removeIndex) {
if (removeIndex < 0 || removeIndex >= amtDonuts) {
cerr << "Invalid index to remove. Index out of range." << endl;
return;
}
// Shift elements to fill the gap
for (int i = removeIndex; i < amtDonuts - 1; ++i) {
donuts[i] = donuts[i + 1];
}
// Decrement the amount of donuts
amtDonuts--;
}
/**
* Outputs information about sold donuts to an output file.
*
* @param outfile The output file stream.
* @param soldDonuts The array of sold donuts.
* @param amtSold The current number of sold donuts in the array.
*/
void outputSoldDonuts(ofstream &outfile, const donutType soldDonuts[],
int amtSold) {
if (!outfile.is_open()) {
cerr << "Error: Output file is not open." << endl;
return;
}
outfile << fixed << setprecision(2);
outfile << "Name,Type,Filling,Topping1,Topping2,Price" << endl;
for (int i = 0; i < amtSold; ++i) {
outfile << soldDonuts[i].name << ",";
outfile << (soldDonuts[i].type ? "Cake" : "Dough") << ",";
outfile << soldDonuts[i].filling << ",";
outfile << soldDonuts[i].toppings[0] << ",";
outfile << soldDonuts[i].toppings[1] << ",";
outfile << soldDonuts[i].price << "\n";
}
}
/**
* Displays the list of available donuts with their names and prices.
*
* @param donuts The array of available donuts.
* @param amtDonuts The current number of available donuts in the array.
*/
void displayAvailableDonuts(const donutType donuts[], int amtDonuts) {
cout << "List of donuts" << endl;
cout << "---------------------------" << endl;
int count = 0;
for (int i = 0; i < amtDonuts; ++i)
cout << donuts[i].name << " " << donuts[i].price << endl;
cout << endl;
}