Question

所以我是C ++的新手。这个想法是它应该为用户提供两个选项，并且任一选项都可以从用户那里读取输入。但是，它们都没有实际读取用户的任何输入，而只是跳到程序的末尾。任何帮助真的很感激！谢谢。

（注意：我知道它与第一个'cin'接受'数字'有关）

#include <stdio.h>
#define SIZE 80
#include <iostream>
int main(void)
{
FILE * pFile;
int c; // variable to hold character input by user
char sentence[SIZE]; // create char array
char filename[SIZE]; //create filename array
int i = 0; // initialize counter i
int number;
std::cout << "Give a number. 1 for file. Anything else for standard.";
std::cin >> number;
std::cin.clear();



if(number==1)
{

    puts("Enter filename to append: ");
    while ((i < SIZE-1) && (c = getchar()) != '\n') {
    filename[i++] = c;}

    filename[i]= '\0';



    //fgetc(sentence,80,stdin);
    pFile=fopen(filename,"a");
    puts("Give a sentence to place in file:");
    while ((i < SIZE-1) && (c = getchar()) != '\n') {
    sentence[i++] = c;}

    sentence[i]= '\0';
    fputs(sentence,pFile);
    fclose(pFile);

    do {
      c = fgetc (pFile);

    } while (c != EOF);
    fclose (pFile);


}
else
{

    // prompt user to enter line of text
    puts("Enter a line of text:");

    // use getchar to read each character
    while ((i < SIZE-1) && (c = getchar()) != '\n') {
    sentence[i++] = c;}

    sentence[i]= '\0';

    // terminate string
    // use puts to display sentence

    puts("\nThe line entered was:");
    puts(sentence);
}


}

Answer 1

我认为你必须删除字符＆＃34;输入＆＃34;来自stdin。尝试：

TABLE SCHOOL

--------+--------+----
No. |NAME    |CLASS  |
--------+--------+----
1.  |Batman  |math   |
--------+--------+----
2.  |Batman  |biology|
--------+--------+----
4.  |Batman  |karate |
--------+--------+----
5.  |Superman|biology|
--------+--------+----
6.  |Superman|karate |
--------+--------+----
7.  |Superman|swim   |
--------+--------+----

TABLE SUPERHERO
--------+-----
No. |NAME    |
--------+-----
1.  |Batman  |
--------+-----
2.  |Superman|
--------+-----

TABLE CLASS

--------+-----
No. |CLASS   |
--------+-----
1.  |Math    |
--------+-----
2.  |biology |
--------+-----
3.  |karate  |
--------+-----
4.  |Swim    |
--------+-----

Answer 2

编写cin.ignore（numeric_limits＆lt; streamsize＆gt; :: max（），＆＃39; \ n＆＃39;）; 代替std :: cin.clear（）会丢弃输入流中的所有内容，包括换行符。

#include <stdio.h> 
#include <iostream> 
#include <ios> // for <streamsize>
#include <limits> // for numeric_limits
#define SIZE 80
using namespace std;
int main(void) {
    FILE * pFile;
    int c; // variable to hold character input by user
    char sentence[SIZE]; // create char array
    char filename[SIZE]; //create filename array
    int i = 0; // initialize counter i
    int number;
    std::cout << "Give a number. 1 for file. Anything else for standard.";
    std::cin >> number;
    //std::cin.clear();
    cin.ignore(numeric_limits < streamsize > ::max(), '\n');

    if (number == 1) {

        puts("Enter filename to append: ");
        while ((i < SIZE - 1) && (c = getchar()) != '\n') {
            filename[i++] = c;
        }

        filename[i] = '\0';

        //fgetc(sentence,80,stdin);
        pFile = fopen(filename, "a");
        puts("Give a sentence to place in file:");
        while ((i < SIZE - 1) && (c = getchar()) != '\n') {
            sentence[i++] = c;
        }

        sentence[i] = '\0';
        fputs(sentence, pFile);
        fclose(pFile);

        do {
            c = fgetc(pFile);

        } while (c != EOF);
        fclose(pFile);
    } else {

        // prompt user to enter line of text
        puts("Enter a line of text:");

        // use getchar to read each character
        while ((i < SIZE - 1) && (c = getchar()) != '\n') {
            sentence[i++] = c;
        }

        sentence[i] = '\0';

        // terminate string
        // use puts to display sentence

        puts("\nThe line entered was:");
        puts(sentence);
    }
}

C ++。似乎没有从用户那里获取输入

2 个答案: