islower| | isdigit| | Isupper

Correlation function Isalpha,isupper Header file #include<ctype.h> define function int islower (int c) function Description Check if parameter c is a lowercase English letter. The return value returns True if the argument C is a lowercase English letter, otherwise null (0) is returned. Additional instructions This is a macro definition, not a real function.

1#include <ctype.h>2 Main ()3 {4charstr[]="[email protected] #FDsP [e?";5 Inti;6  for(i=0; str[i]!=0; i++)7 if(Islower (Str[i])) printf ("%cisalower-casecharacter\n", Str[i]);8}

IsDigit
Table header File	#include <ctype.h>
Defining functions	int isdigit (char c)
Function description	Check whether the parameter C is Arabic numerals 0 to 9.
return value	Returns true if the argument C is an Arabic numeral, otherwise null (0) is returned.
Additional Instructions	This is a macro definition, not a real function.

1#include <ctype.h>2 Main ()3 {4   Charstr[]="[email protected] #FDsP [e?";5   inti;6     for(i=0; str[i]!=0; i++)7     {8      if(IsDigit (Str[i]))9printf"%c is an digit character\n", Str[i])Ten      } One}

Prototype: extern int isupper (int c); header file: ctype.h function: Determines whether the character C is uppercase English letter description: When the parameter C is capitalized English letter (A-Z), returns a value other than 0, otherwise returns zero. Additional notes: This is a macro definition, not a real function.

#include <ctype.h>#include<stdio.h>intMain () {Chartest[]="A1b2c3d4"; Char*POS; POS=Test;  while(*pos!=0)    {        if(Isupper (*POS)) printf ("%c",*POS); POS++; } printf ("\ n"); return 0;}

islower| | isdigit| | Isupper