用c语言读取文件

[w372011482]

#include <tchar.h>
#include <iostream>
#include <fstream>
#include <conio.h>
using namespace std;

const int MAX_ARRAY_SIZE = 10;
void fillArray(double a[], int size, int& numberUsed);
void showArray(const double a[], int numberUsed);

int _tmain(int argc, _TCHAR* argv[])
{
double dblArray[MAX_ARRAY_SIZE];
int numberUsed;
cout << "\n\t请选择需要打开的文件名：\n\n";

fillArray(dblArray, MAX_ARRAY_SIZE, numberUsed);
showArray(dblArray, numberUsed);

cout << endl << "请按任意键继续...";
getch();
return 0;
}

void fillArray(double a[], int size, int& numberUsed)
{
ifstream inStream; // To read in file
char fileName[20]; // name of file
cout << "\n\nPlease enter a file name from the following: \n\n";
system("dir /B *.txt"); // list text files in directory

cout << "\n\nPlease enter a file name: ";
cin >> fileName; // Read in the file name
cout << endl << endl ;
inStream.open(fileName);

int index = 0;
numberUsed = 0;
while ( ! inStream.eof() && index < size )
{
inStream >> a[index];
index++;
}
inStream.close();
numberUsed = index;
}

void showArray(const double a[], int numberUsed)
{
cout << "Array has the following values: \n\n";

cout << "\tIndex\tValue\n";
for (int index = 0; index < numberUsed; index++)
{
cout << "\t" << index << "\t"
<< a[index] << endl;

}
}
谁能把这个程序改成c语言版的？我失败了。

[Ol_lO]

fscanf，fread

[hongwenjun]

既然用C++ 就直接用 fstream 吧，用起来比 C的简单点

[aszxqw]

c语言读取的话我最经常用的方法是
先用 freopen("C:\\Users\\Desktop\\1.txt","r",stdin);
然后用scanf它会自动从那文件中读取。

[浮尘grass]

//#include <tchar.h>
//#include <iostream>
//#include <fstream>
//#include <conio.h>
//using namespace std;
#include <stdio.h>
#include <stdlib.h>
const int MAX_ARRAY_SIZE = 10;
void fillArray(float a[], int size, int& numberUsed);
void showArray(const float a[], int numberUsed);

int main()
{
	float dblArray[MAX_ARRAY_SIZE];
	int numberUsed;
	//cout << "\n\t请选择需要打开的文件名：\n\n";
	printf("\n\t请选择需要打开的文件名：\n\n");

	fillArray(dblArray, MAX_ARRAY_SIZE, numberUsed);
	showArray(dblArray, numberUsed);

	//cout << endl << "请按任意键继续...";
	printf("请按任意键继续...");
	//getch();
	return 0;
}

void fillArray(float a[], int size, int& numberUsed)
{
	FILE *fp;
	// ifstream inStream; // To read in file
	char fileName[20]; // name of file
	//cout << "\n\nPlease enter a file name from the following: \n\n";
	printf("\n\nPlease enter a file name from the following: \n\n");
	system("dir /B *.txt"); // list text files in directory

	//cout << "\n\nPlease enter a file name: ";
	printf("\n\nPlease enter a file name:");
	//cin >> fileName; // Read in the file name
	scanf("%s", fileName);

	//cout << endl << endl ;
	//inStream.open(fileName);

	fp = fopen(fileName,"r");
	if (!fp)
		return;
	int index = 0;
	numberUsed = 0;
	//while ( ! inStream.eof() && index < size )
	while ((fscanf(fp, "%f", &a[index]) != EOF) && index < size)
	{
		//inStream >> a[index];
		index++;
	}
	//inStream.close();
	fclose(fp);
	numberUsed = index;
}

void showArray(const float a[], int numberUsed)
{
	//cout << "Array has the following values: \n\n";
	printf("Array has the following values: \n\n");
	//cout << "\tIndex\tValue\n";
	printf("\tIndex\tValue\n");
	for (int index = 0; index < numberUsed; index++) 
	{
		//cout << "\t" << index << "\t"
		//<< a[index] << endl;
		printf("%d\t%f\t",index, a[index]); 

	}
}