关于C语言char函数的基本问题?

Question

#include "stdio.h"void main(){char c;printf("please input a character:");c=getchar(); if(c < 32){printf("This is a control character\n");}else if("c >= '0' && c<='9'"){printf("This is an integer\n");}else if ("c>='a' && c<= 'z'"){printf("This is a small letter\n");}else if ("c>='A' && c<='Z'"){printf("This is a capital letter\n");}else{printf("This is another character\n");}}这个程序我本来是想随便输一个符号就能帮我自动归类但是不管输入什么都说这是一个整数怎么回事?

Answer 1

#include "stdio.h"

void main()

{
char c;
printf("please input a character:");
c=getchar();
if(c < 32)
{
printf("This is a control character\n");
}
else if((c >= '0') && (c<='9'))
{
printf("This is an integer\n");
}
else if ((c>='a') && (c<= 'z'))
{
printf("This is a small letter\n");
}
else if ((c>='A') && (c<='Z'))
{
printf("This is a capital letter\n");
}
else
{
printf("This is another character\n");
}
}

Answer 2

if("c >= '0' && c<='9'")这里的双引号是干什么的？应该是if(c >= '0' && c<='9')