Question

我正在研究我们的班级中的c语言，我创建了一些代码来查找其他数组内的一些数字，但是当我使用char值尝试它时，我的代码无法与使用int值一起工作。

这是我的代码：

#include<stdio.h>

int main () {
    int  num, i, j;
    char a[99], ele;

    printf("Enter the Character element:");
    // get the length of array by the num value
    scanf("%d", &num);

    printf("Enter the values: \n");
    // a loop for getting values for our a[array] line by line
    for ( i = 0 ; i < num ; i++ ) {
        // get value by index i for array a index by index
        //printf("%d\t", (i+1));
        //if ( i + 1  == num ) {
        //    scanf("%c", &a[i]);
        //} else {
            scanf("%c", &a[i]);
        //}

    }

    printf("Enter the Character elements to be searched:");
    // get the value for ele, to use ele for searching inside our a[array]
    scanf("%c", &ele);

    // we need to set i to 0 for our while loop
    j = 0;
    // use the while loop to
    while ( j < num && ele != a[j]) {
        j++;
    }
    if ( j < num ) {
        printf("Character found at the location = %d\n\n\n", j + 1);
    } else {
        printf("Character Not Found!\n\n\n");
    }
    return 0;

}

我尝试修复很多次，但是每次遇到错误时，上面的代码就可以正常工作，但是在输入过程中会遇到一些输入值。

Answer 1

感谢WhozCraig，user3121023的建议，scanf(" %c", &a[i]);和scanf(" %c", &ele);中的空格会引起一些不必要的输入，因此这是我的代码，它的工作原理很吸引人。：））

我只是在%c前添加空格，一切正常。

#include<stdio.h>

int main () {
    int  num, i, j;
    char a[99], ele;

    printf("Enter the Character element:");
    // get the length of array by the num value
    scanf("%d", &num);

    printf("Enter the values: \n");
    // a loop for getting values for our a[array] line by line
    for ( i = 0 ; i < num ; i++ ) {
        // get value by index i for array a index by index
        printf("%d\t", (i+1));
        scanf(" %c", &a[i]);


    }

    printf("Enter the Character elements to be searched:");
    // get the value for ele, to use ele for searching inside our a[array]
    scanf(" %c", &ele);

    // we need to set i to 0 for our while loop
    j = 0;
    // use the while loop to
    while ( j < num && ele != a[j]) {
        j++;
    }
    if ( j < num ) {
        printf("Character found at the location = %d\n\n\n", j + 1);
    } else {
        printf("Character Not Found!\n\n\n");
    }
    return 0;

}

Answer 2

您的程序中存在一个导致意外行为的问题：

scanf("%d", &num)从标准输入中读取一个数字，但保留用户键入的换行符作为下一个要读取的字符。
对scanf("%c", &a[i]);的进一步调用从用户读取了此待定换行符和另外num-1个字符，而其余的输入待定...
最后一个scanf("%c", &ele);读取stdin中待处理的任何字节，无论是来自用户的字符还是待处理的换行符。

因此，程序的行为就好像它没有执行最后一个scanf()。

您应该使用fgets()每次从用户一行读取输入，或使用循环刷新挂起的换行符：

#include <stdio.h>

int main() {
    int num, i, c;
    char a[99], ele;

    printf("Enter the number of character:");
    // get the length of array by the num value
    if (scanf("%d", &num) != 1 || num < 0 || num > 99)
        return 1;

    // consume the rest of the line typed by the user
    while ((c = getchar()) != EOF && c!= '\n')
        continue;

    printf("Enter the characters on a single line: \n");
    // a loop for getting values for our a[array]
    for (i = 0; i < num; i++) {
        if (scanf("%c", &a[i]) != 1)
            return 1;
    }

    // consume the rest of the line typed by the user
    while ((c = getchar()) != EOF && c!= '\n')
        continue;

    printf("Enter the character to be searched: ");
    // get the value for ele, to use ele for searching inside our a[array]
    if (scanf("%c", &ele) != 1)
        return 1;

    // consume the rest of the line typed by the user
    while ((c = getchar()) != EOF && c!= '\n')
        continue;

    // use a for loop
    for (i = 0; i < num && ele != a[i]; i++) {
        i++;
    }
    if (i < num) {
        printf("Character %c found at the offset %d\n\n\n", ele, i);
    } else {
        printf("Character %c Not Found!\n\n\n", ele);
    }
    return 0;
}

在C中的char数组中搜索char值

2 个答案: