Question

由于某种原因，我无法在程序中打印出“ *”。我想打印*如果满足条件。条件是当天的降雨量是否大于平均降雨量。

在平均值栏中，我得到了奇怪的符号。我试图调试到小数点，并得到-112 ascii。我不明白，但我尝试研究！

我是C的新手，请谅解。就像2天前一样刚刚学习！！

这是我的代码：

//Assignment one 9/20/2018
//Anthony Lomaistro and David Luong 
//luongd5@student.lasalle.edu
//lomaistroa1@student.lasalle.edu

#include <stdio.h>
main() {
    int n = 0; //counters for the loops
    int x = 0; // counter for the loops 
    int counter = 0; // counter whenever i need to keep track of increments
    int days_input = 0; // how many days we are keeping track of
    int number_of_days = 0;
    double rainfall_input = 0;
    double rainfall_amount = 0; // how much rainfall per day
    double rainfall_average = 0; // average of rainfall
    double rainfall_total = 0;
    double rainfall_counter = 0; // count how many days it rained above the average
    int correct = 0;
    double rainfall_array[50];//array that contains the user input
    char rainfall_condition[50]; // array that contains the *

    double sum = 0;
    double average = 0;
    double percent_days = 0; //rainfall % above average
    double valid = 0;
    double valid2 = 0;

    printf("Welcome to Lomaistro and Luong's Rainfall Program \n");

    printf("How many days would you like to keep track of? Please enter a value between 1 and 50: #%d:", n + 1);

    //printf(number_of_days);

    while (valid == 0) {
        scanf_s("%d", &number_of_days);
        if ((number_of_days > 50) || (number_of_days <= 0)) { // come back to this, this doesnt do anytihng
            printf("Invalid value, please enter in a day that is between 1 and 50 \n");
        }
        else {
            valid = 1;
        }
    }

    //getting the user to enter in the rainfall 
    for (x = 0; x < number_of_days; x = x + 1) {
        valid2 = 0;
        while (valid2 == 0) {
            printf("Enter rainfall (in inches): ");
            scanf_s("%lf", &rainfall_amount);
            if ((rainfall_amount >= 0) && (rainfall_amount <= 10)) {
                valid2 = 1;
                rainfall_array[x] = rainfall_amount;

            }
            else
                printf("Please enter in a valid rainfall amount between 1 and 10");
        }
    }
    //computing average
    for (n = 0; n < number_of_days; n = n + 1) {
        sum += rainfall_array[n];
        average = sum / number_of_days;
    }
    printf("Mean daily rainfall(in inches): %lf", average);

    //seeing if the * should be the array or not
    for (n = 0; n < number_of_days; n = n + 1) {
        if (rainfall_array[n] > average) {
            rainfall_condition[n] = "*";
            rainfall_counter = rainfall_counter + 1;
        }
        else
            rainfall_condition[n] = "empty";
    }

    // print out the thing
    printf("\n Days \t Amount \t >Mean \n");
    printf("==============================\n");
    for (n = 0; n < number_of_days; n = n + 1) {
        printf("%d \t %f \t %c \n", n + 1, rainfall_array[n], rainfall_condition[n]);

    }
    percent_days = rainfall_counter / number_of_days;
    percent_days = percent_days * 100;
    printf("Number of days that rained above average : %f \n", rainfall_counter);
    printf("Percentage of days that rained above average: %f%% \n", percent_days);
    system("pause");
}

Answer 1

rainfall_condition是char的数组，但是使用"*"时要在其中放置指向字符串文字的指针。请将'*'用作字符文字。更具体地说，这一行：

        rainfall_condition[n] = "*";

应该是：

        rainfall_condition[n] = '*';

在编译器中打开一些警告；第一行（现在的内容）不是有效的C代码，因此您应该会看到一条诊断消息。

编辑：既然我已经阅读了更多代码，看来您想要在该列中使用*还是empty？在这种情况下，您要将变量声明更改为：

char *rainfall_condition[50]; // array that contains the *

然后将打印语句更改为：

    printf("%d \t %f \t %s \n", n + 1, rainfall_array[n], rainfall_condition[n]);

无法在C中打印“ *”

1 个答案: