A method of determining whether a character is a blank or special character in C language _c language

C language Isspace () function: To determine whether a character is a white space character
header file:

#include <ctype.h>

To define a function:

int isspace (int c);

Function Description: Check that parameter C is a space character, that is, whether it is a space ('), a positional character (' \ t '), a CR (' \ R '), a newline (' \ n '), a vertical positioning character (' \v '), or a page (' \f ').

Return value: If the parameter C is a white-space character, it returns a non-0, otherwise it returns 0.

Additional description: This is a macro definition, not a true function.

Example: Locate the space character contained in the string str[] and display the ASCII code for the space character.

#include <ctype.h>
Main () {
  char str[] = "123c @# fd\tsp[e?\n";
  int i;
  for (i = 0; Str[i]!= 0. i++)
    if (Isspace (str[i)))
      printf ("str[%d" is a white-space character:%d\n ", I, Str[i]); 
   }

Execution results:

STR[4] is a white-space character:32
str[7] is a white-space character:32 str[10
] is a white-space character:9// \ t
str[16] is a white-space character:10//\ t

C language Ispunct () function: To determine whether a character is a punctuation mark or special character
header file:

#inlude <ctype.h>

The ispunct () function is used to detect whether a character is a punctuation mark or special character, and its prototype is:

  int ispunct (int c);

"Parameter" C is the character you want to detect.

Return value if C is a punctuation mark or special symbol (non-space, non-numeric, and non-English letters) returns a value other than 0, or 0.

Note that this is a macro definition, not a true function.

"Instances" lists punctuation marks or special symbols in string str.

#include <stdio.h>
#include <ctype.h>
int main ()
{
  int i=0;
  int cx=0;
  Char str[]= "Hello, welcome!";
  while (Str[i])
  {
    if (ispunct (str[i)) cx++;
    i++;
  }
  printf ("sentence contains%d punctuation characters.\n", CX);
  return 0;
}

Output results:

Sentence contains 2 punctuation characters.