课后习题4.3

/*Exercise 4.3 Displaying printable characters plus whitspace names */
#include <stdio.h>
#include <ctype.h>

int main(void)
{
??? int i = 0 ;
? char ch = 0;?????????????????????? /* Character code value */
? for( i = 0 ; i<128 ; i++)
? {
??? ch = (char)i;
??? if(ch%2==0)
????? printf("\n");
??? printf("? %4d",ch);
??? if(isgraph(ch))
????? printf("?????????????? %c",ch);
??? else
????? switch(ch)
??? {
??????? case '\n':
?????????? printf("???????? newline",ch);
?????????? break;
??????? case ' ':
?????????? printf("?????????? space",ch);
?????????? break;
??????? case '\t':
?????????? printf("? horizontal tab",ch);
?????????? break;
??????? case '\v':
?????????? printf("??? vertical tab",ch);
?????????? break;
???????? case '\f':
?????????? printf("?????? form feed",ch);
?????????? break;
??????? default:
?????????? printf("??????????????? ");
?????????? break;

??? }

? }
? printf("\n");
??? return 0;
}