如何在c中为if语句提供数组输入？

Question

# include <stdio.h>


void danidev(void){
 printf("Dani is a YouTuber and an indie game developer and an fps game developer having his game published in play store he is 22 years old and goes to a university");
}

void brackeys(void){
    printf("brackeys is a YouTuber and an indie game developer and also an fps game developer having most of his games published in itch.io and has a team which works on game development");
}

void blackthornprod(void){
    printf("  they are two brothers who create video games and teach others how to do the same over on Youtube and Udemy ! they are passionate in sharing their knowledge and game creation journey with other aspiring game developers.");
}

void jabrils(void){
 printf("jabrils is a ai programmer and also a machine learning pro coder and also a game developer he has made a lot of ai and has saved millions of people from their tough times");
}

void codingbullet(void){
 printf("coding bullet is a multi intelligent ai developer and also a master in machine learning also he owns a youtube channel with 2.06 million subscribers");
}

int main(){

 printf("HERE IS THE INFORMATION OF FAMOUS CODING YOUTUBERS(PLS TYPE THE FOLLWOING YOUTUBERS NAME): ");
 char b;
 scanf("%c",&b);
 if(b=='danidev'){
 danidev(); 
 }
 else if(b=='brackeys'){
 brackeys();
 }
 else if(b=='blackthornprod'){
 blackthornprod();
 }
 else if(b=='jabrils'){
 jabrils();
 }
 else if(b=='codingbullet'){
 codingbullet();
 }
 else{
 printf(" i dont know what you are taking about");
 }

return 0;
}

我有一个问题，当我输入一个YouTubers名称(完整名称)作为输入，我得到一个问题，常量太长，没有给出正确的结果，而且它还说常量字符对于它的类型来说太长

Answer 1

您需要为输入分配更多的空间。类型char只能包含一个字符。您需要一个由char组成的数组。可以这样声明：

char b[30];

这将包含30个字符。

对于字符串文字，您应该使用双引号而不是单引号。例如"danidev"，而不是'danidev'。

在比较字符串(字符数组)时，应该使用strcmp()函数。

请阅读相关文档：strcmp

由于您是初学者，我还建议您查看一些关于C. String Functions中字符串的教程。

Answer 2

不能使用相等运算符(==)直接比较字符串。相反，可以使用strcmp()来比较两个字符串。

char str[20];
gets(str);

if(!strcmp(str, "danidev") danidev();  //Use double quotes for strings, instead of single quotes (used for character literal).
//Same as strcmp(str, "danidev") == 0
//rest of the code

另外，如果你是初学者，我建议你检查一些C的字符串库函数。

Answer 3

有几个错误，来自字符串比较、字符串定义和char/char数组变量。它有时看起来像JS，但要注意较大的差异。除此之外，我已经看到在我写这篇文章的时候已经添加了另一个答案，我想添加注意scanf中数组的长度，这样你就不会在运行时引发缓冲区溢出错误。

你可以在这里查看：https://onlinegdb.com/HyrgvK-sL

#include <stdio.h>
#include <string.h>

void danidev (void)
{
  printf ("Dani is a YouTuber and an indie game developer and an fps game developer having his game published in play store he is 22 years old and goes to a university");
}

int main ()
{

    printf("HERE IS THE INFORMATION OF FAMOUS CODING YOUTUBERS(PLS TYPE THE FOLLWOING YOUTUBERS NAME): ");
    char b[32];
    scanf("%31s", b);

    if (strncmp(b,"danidev", 32)== 0) 
    {
        danidev ();
    }
    else
    {
        printf (" i dont know what you are taking about");
    }
    return 0;
}