Counting vowels

I have to write a program that takes a series of alphabets and displays the repeating vowels and their corresponding occurrence. The input can be either lower case or upper case. For help, i can convert upper case to lower case and vice versa without affecting other characters.

Sample input: AsdatEhjTeEUuklIti
Sample output: Repeating vowels are
a 2
e 3
i 2
u 2

I came up with this code:

Code:

#include <stdio.h>


char tolower(char p);
char toupper(char p);


int main()
{


    int z,p=1,a=0,i=0,o=0,u=0,e=0, f;


    char alpha[p];
    char conv[f];


    printf("\n Enter characters : \t");


    while(scanf("%c",&alpha[p])!=EOF)
    {
        if(alpha[p]='A'||'E'||'I'||'O'||'U')
        {
            conv[f]=tolower(alpha[p]);
        }


        switch (conv[f])
        {


        case 'a' :
        {
            a++;
            break;
        }
        case 'e' :
        {
            e++;
            break;
        }
        case 'i' :
        {
            i++;
            break;
        }
        case 'o' :
        {
            o++;
            break;
        }
        case 'u' :
        {
            u++;
            break;
        }


        default :
        {
            break;
        }
        }
        f++;


    }

    printf("\n a=\t %d",a);
    printf("\n e=\t %d",e);
    printf("\n i=\t %d",i);
    printf("\n o=\t %d",o);
    printf("\n u=\t %d",u);

    return 0;
}


char toupper(char p)
{
    int x;
    x = (int)p - 32;


    return x;
}


char tolower(char p)
{
    int x;
    x = (int)p + 32;


    return x;
}

Any idea how to proceed to a right solution? Thanks

Your code has following errors:

wrong declaration of array inside main

Code:

    char alpha[p];
    char conv[f];

and..
The if condition

Code:

if(alpha[p]='A'||'E'||'I'||'O'||'U')

I did some modification in your code and I think its working now.. check this out

Code:

#include <stdio.h>


char tolower(char p);
char toupper(char p);


int main()
{


    int p=0,a=0,i=0,o=0,u=0,e=0, f;

    char alpha[20];

    printf("\n Enter characters : \t");
 
   scanf("%s",&alpha);
    
    while( alpha[p]!=EOF)
     {
        if(alpha[p]=='A'||alpha[p]=='E'||alpha[p]=='I'||alpha[p]=='O'||alpha[p]=='U')
        {
            alpha[p]=tolower(alpha[p]);
        }


        switch (alpha[p])
        {


        case 'a' :
        {
            a++;
            break;
        }
        case 'e' :
        {
            e++;
            break;
        }
        case 'i' :
        {
            i++;
            break;
        }
        case 'o' :
        {
            o++;
            break;
        }
        case 'u' :
        {
            u++;
            break;
        }
        }  //End of Switch
        p++;


    }  //End of While

    printf("\n a=\t %d",a);
    printf("\n e=\t %d",e);
    printf("\n i=\t %d",i);
    printf("\n o=\t %d",o);
    printf("\n u=\t %d",u);

    return 0;
}  //End of Main


char toupper(char p)
{
    int x;
    x = (int)p - 32;


    return x;
}


char tolower(char p)
{
    int x;
    x = (int)p + 32;


    return x;
}

Yes it does work. I did not know about that if. Thanks

> scanf("%s",&alpha);
You should drop the &
alpha is an array of char, so there is no need for an address operator here.
If alpha were an actual char* (pointing to some memory), then using & would make it very wrong.

> while( alpha[p]!=EOF)
EOF is returned by FILE* stream functions, it is never stored in a string. \0 marks the end of strings.

> case 'a' :
Saying
case 'a' : case 'A':
would save all the toupper stuff.

> x = (int)p - 32;
This assumes an ASCII character set (look up EBCDIC)
Besides, portable versions are in ctype.h