用ASCLL判断输入元素

数字0-9的ASCII码为：048到057
大写字母A-Z的ASCII为：065-090
小写字母a-z的ASCII为：097到122

判断字符是数字还是大小写字母

int main()

{

        input=getchar();//获取输入的字符
        if(input <= 32)
                printf("You have input a control  character!!
");
        else if(input >= 48 && input <= 57)    //数字；
        {
                for( i=48;i<58;i++)
                {
                        if(input==i)
                                break;
                }
                printf("You put a number,ranging from 0--9!
 The number is %d!
 ",i);
        }
        else if(input >=65 && input <=90 )  //大写字母；
        {
                for( i=65; i<=90; i++)
                {
                        if(input==i)
                                break;
                }
                printf("You have put a uppercase! Ranging from A--Z!
The number is %d!
",i);
        }
        else if(input >=97 && input <=122)   //小写字母
        {
                for( i=97;i<=122;i++)
                {
                        if(i==input)
                                break;
                }
                printf("You have input a lowercase! Ranging from a--z!
The number is %d
",i);
        }
        else  
                printf("You have input a other character!
");
        }