C语言程序中，如何区分字符是数字还是字母？

char ch;
ch=getchar();
if(ch>='0'&&ch<='9')
printf("数字");
if(ch>='a'&&ch<='z'||ch>='A'&&ch<='Z')
printf("字母");

2.

#include <stdio.h>
int main(){
char char1 = 184;
char char2 = 246;

printf("Print1:\n");

printf("%c",char1);

printf("\n");

printf("%c", char2);

printf("\n Print2:\n %c%c\n",char1, char2);

printf(" Print3:\n ");

printf("%c",char1);
printf("%c",char2);

return 0;
}

让我们来看一下结果：         

所以我们还可以这样玩：

#include <stdio.h>
#include <unistd.h>//VC退散

int main(){

char hexchar[19] = {0xc1,0xd6,0xb2,0xd3,0xb1,0xf3,0x2c,0x20,0x49,0x20,0x4c,0x6f,,0x76,0x65,0x20,0x59,0x6f,0x75,0x21},i;

for(i=0;i<19;i++){
printf("%c",hexchar[i]);
_sleep(300);
}
return 0;
}