Thread: Checking user input [int/char] (Help)

I was wondering if I can make a program which would print "its a number" when the user enters a number and prints "Its an alphabet" when an user enters an alphabet.
Can you make a simple C program which can do that?

I am a newbie in programming so please explain what you write.

Originally Posted by Salem

Announcements - C Programming
Presumably, you've got as far as being able to read input, and print what was read.
If so, then post this much to at least prove you've been paying attention in class.

If you can't do that, then re-read your material and make some kind of effort.

This forum is NOT a place to dump your assignment and expect a complete answer on a plate.

As much I can make is

Code:

#include<stdio.h>
#include<conio.h>
void main()
int i;
printf("Enter something");
i=getchare();
if(i>=1)
puts("You have entered a number");
else if((i=='a')||(i=='b')) // and so on to Z.
puts("You have entered an alphabet");
else
puts("Invalid input");
}

The problem is in the declaration

Code:

int i;

Because if i is an int then it cant store a char.....
If a user enters a char then it will convert it to its ASCII value i.e. a number value so in both the cases i will be an integer.
so the output will always be You have entered a number.
So How can I fix that.

Originally Posted by Salem

Look in ctype.h for isascii() etc.

Can you explain

Originally Posted by Salem

Look in ctype.h for isascii() etc.

isascii

short isascii (short c);

Checks whether a character is an ASCII character.
isascii returns nonzero if c is in the range 0 to 127 (0x00-0x7F), otherwise it returns zero. It is a simple macro.

I dont think that it will help. because it only checks if the number is an ASCII number.

Thats not my solution.

Plz read my conditions and program and then post a helpful reply.

You can take time, I am not in hurry Its not my homework, its only for general knowledge.

Originally Posted by laserlight

One of your two conditions is probably wrong: I guess that by "alphabet", you mean "letter" in the English alphabet.

Yeah , its character/letter.

Originally Posted by laserlight

Right. So what else did you find from <ctype.h>?

All I found in it was:

_tolowerTranslates uppercase characters to lowercase._toupperTranslates uppercase characters to lowercase.isalnumChecks whether a character is an alphanumeric.isalphaChecks whether a character is a letter.isasciiChecks whether a character is an ASCII character.iscntrlChecks whether a character is a control character.isdigitChecks whether a character is a digit.isextalnumChecks whether a character is an extended alphanumeric.isextlowerChecks whether a character is a lowercase, including foreign ones.isextpunctChecks whether a character is an extended punctuation character.isextupperChecks whether a character is an uppercase, including foreign ones.isfrgnChecks whether a character is a foreign letter.isfrgnalnumChecks whether a character is a foreign letter which is valid in a variable name.isfrgnlowerChecks whether a character is a foreign lowercase.isfrgnupperChecks whether a character is a foreign uppercase.isgraphChecks whether a character is a graph character.isGreekChecks whether a character is a Greek letter.islowerChecks whether a character is a lowercase.isprintChecks whether a character is a printing character.ispunctChecks whether a character is a punctuation character.isspaceChecks whether a character is a white space.isupperChecks whether a character is an uppercase.isxdigitChecks whether a character is a hex digit.toasciiTranslates characters to ASCII format.toextlowerTranslates characters to lowercase, including foreign ones.toextupperTranslates characters to uppercase, including foreign ones.tolowerTranslates characters to lowercase.toupperTranslates characters to uppercase.
<a href="http://google.com">Just testing HTML</a>

You're getting warmer. Do any of those seem like they might be useful for your program?

Originally Posted by Matticus

Do any of those seem like they might be useful for your program?

I don't think that anyone of this would help

This's not use lib , like this:

Code:

#include<stdio.h>
int main(int argc, char *argv[])
{
    int i;
    printf("Enter something: ");
    i=getchar();
    if(i >= '0' && i <= '9')
        puts("You have entered a number");
    else if((i >='a' && i <= 'z') || (i >='A' && i <= 'Z')) // 
        puts("You have entered an alphabet");
    else
        puts("Invalid input");
}