修复此 if,else 语句 [英] Fixing this if,else statements

问题描述

问题似乎出在

第 18 行:警告:指针和整数之间的比较
第 22 行:错误:'else' 之前的预期表达式

Line 18: warning: comparison between pointer and integer
Line 22: error: expected expression before 'else'

我做错了什么?有更好的方法吗?

What am I doing wrong? Is there a better way of doing this?

#include <stdio.h>

int main(void)
{
    char pname[25];
    char Y[1];
    char N[1];
    char choice[1];

    printf("when responding to Yes or No questions use Y/N.
");
    printf("Hello,traveler Welcome to the Castle of Atal...."
            "What is your name?
");
    scanf("%s", &pname);

    printf("Greeting's %s What bring's you to the kingdom of Tharnos?
",
            pname);
    printf("I see how intresting do you wish to enter %s ?
", pname);
    scanf("%c", &choice);

    if (choice == 'Y');
        printf("Enter %s...
", pname);
    else (choice == 'N');
        printf("Farewell lost soul!
");

    return 0;
}

推荐答案

在您的代码中，更改定义

In your code, change the definitions

char Y [1];
char N [1];
char choice[1];

到

 char Y;
 char N;
 char choice;

否则，在当前定义下，choice 表示一个 array(1 个元素)，其中

Otherwise, with the current definition, choice represents an array (of 1 element), which

• 这里不需要，单个 char 就可以了.
• 将触发执行 choice == 'Y' 的警告，因为您无法将数组与 == 运算符进行比较.

• is not required here, a single char will work just fine.
• will trigger the warning for doing choice == 'Y', because, you cannot compare array with == operator.

也就是说，

1. scanf("%c",&choice); 应该是 scanf("%c",&choice); 以避免前面的 换行.
2. scanf ("%s",&pname); 应为 scanf ("%24s",pname); 以避免缓冲区溢出.

1. scanf ("%c",&choice); should be scanf (" %c",&choice); to avoid the previous newline.
2. scanf ("%s",&pname); should be scanf ("%24s",pname); to avoid buffer overrun.

并且，正如 @iharob 先生 在回答中提到的，

and , as mentioned in the answer by Mr. @iharob,

1. if (choice == 'Y');应该是 if (choice == 'Y')(把 ; 去掉)，否则，if 语句实际上是无用的.
2. else 没有条件表达式评估.不过，您可以使用 else if(choice == 'N').

1. if (choice == 'Y');should be if (choice == 'Y') (the ; removed), otherwise, the if statement is effectively useless.
2. There is no conditional expression evaluation for else. You can make use of else if(choice == 'N'), though.

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