c - 添加程序在我给它输入时崩溃

Question

我是 C 初学者，这是迄今为止我最大的程序。它包含 do while 循环以重新启动程序，允许用户添加任意​​数量的数字并确保提交正确的字母以表示是或否。很简单。问题是，我键入的每个数字加起来都是 0.00，无论我选择重新启动，程序都会给我一个段错误(核心转储)错误。

错误:

我很清楚这可能是我忽略的一些愚蠢的细节，但请耐心等待!非常感谢您的帮助。

代码:

/*Basic addition program*/
/*May 31 2018*/
#include <stdio.h>
#include <stdlib.h>
#include<string.h>
int main()
{
    char restart;

//Loop for restart
do{
    /*
    Starts Variables for Current number, sum,
    number place count, and restart choice
    */
    float currnum, sum;
    int count = 1;
    char restart = 'N';

    //Loop for user input amount until 0 is submitted
    do{

    //Initiates number place ending array
    char end[3];

    printf("Basic Addition Program\nType 0 To Terminate\n\n");

    //Chooses which ending to add to array
    if(count == 1){
        strcpy(end, "st");
    }else if(count == 2){
        strcpy(end, "nd");
    }else if(count == 3){
        strcpy(end, "rd");
    }else if(count > 3){
        strcpy(end, "th");
    }

    //Requests user input and adds to current number float
    printf("Enter %d%s number: ", count, end);
    scanf(" %d", &currnum);

    //Clears Screen (Unix)
    system("clear");

    //Adds current number to overall sum
    sum += currnum;

    //Increases number count so that places shift by 1 (e.g 1st to 2nd)
    count++;


    }while(currnum != 0);

    //States numbers inputted and sum
    printf("You added %d numbers and got a sum of %.2f\n", count, sum);

    //Do while loop for user error
    do{
        printf("Restart?(Y/N): ");
        scanf(" %c", restart);

        //Tests if numbers have ben inputted in lowercase and corrects accordingly
        if(restart == 'y'){
            restart = 'Y';
        }else if(restart == 'n'){
            restart = 'N';
        }
    }while(restart != 'Y' || restart != 'N' );

    }while(restart == 'Y');

    return 0;
}

Answer 1

有问题的陈述之一是

scanf(" %c", restart); /* you need to provide the &(address) to store */

应该是

scanf(" %c", &restart);

您应该阅读编译器警告并自行解决并使用 -Wall 标志进行编译。

还有下面的声明

scanf("%d", &currnum); /* currnum is declared as float variable, use %f */

在下面的代码块中

char restart;
do {

 /* some code */
}while(restart == 'Y');

restart 未初始化，您的编译器可能会警告您

error: ‘restart’ is used uninitialized in this function [-Werror=uninitialized]

所以在最开始的时候像restart一样初始化

char restart = 'Y';

最后，如果您想正确学习 C，请将所有警告视为错误，然后开始解决问题。例如像下面这样编译

gcc -Wall -pedantic -Wstrict-prototypes -Werror test.c