Preview
Character functions in C
Character functions need ctype.h header file to be included in the pgoram. Different character functions provided by C Language are:
1. isalpha():
This function checks whether the character variable/constant contains alphabet or not.
2. isdigit()
This function checks whether the character variable/ constant contains digit or not.
3. isalnum()
This function checks whether the character variable/constant contains an alphabet or digit.
4. ispunct()
This function checks whether the character variable/constant contains a punctuator or not. Punctuators are comma, semicolon etc.
5. isspace()
This function checks whether the character variable/constant contains a space or not.
Program to demonstrate the use of character functions. |
#include<ctype.h> #include<stdio.h> int main() { char n; printf("\nEnter a character="); n=getche(); if(isalpha(n)) printf("\nYou typed an alphabet"); if(isdigit(n)) printf("\nYou typed a digit"); if(isalnum(n)) printf("\nYou typed an alphabet or digit"); if(isspace(n)) printf("\nYou typed a blank space"); if(ispunct(n)) printf("\nYou typed punctuator"); return(0); }
Output |
Enter a character=A You typed an alphabet |
6. isupper()
This function checks whether the character variable/constant contains an capital letter alphabet or not.
7. islower()
This function checks whether the character variable/constant contains a lowercase alphabet or not.
8. toupper()
This function converts lowercase alphabet into uppercase alphabet.
9. tolower()
This function converts an uppercase alphabet into lowercase alphabet.
Program to use of islower,isupper,tolower(),toupper(). |
#include<ctype.h> #include<stdio.h> int main() { char n; printf("\nEnter an alphabet="); n=getche(); if(islower(n)) n=toupper(ch); else ch=tolower(ch); printf("\nNow alphabet=%c",n); return(0); }
Output |
Enter an alphabet=A Now alphabet=a |