Recursive function

[mkdl750]

i need help with this one:

#include <stdio.h>
#include <string.h>
char CountEvenASCII(char str[255], int a, int x);

main()
{
    char w[255];
    int num1, num2;
    printf("Input character string: ");
    scanf("%s", w);
    CountEvenASCII(w, num1, num2);
    getch();
    return 0;
}

char CountEvenASCII(char str[255], int a, int x)
{
    a = x = 0;
    if (str[x] % 2 == 0)
    {
        a = (str[x] + a);
    }
    x++;
    printf("\n%d\n\n",a);
    CountEvenASCII(str,a,x);
}

It should display the number of letters with even ASCII values. Please tweak this one for me.

[MacGyver]

How about you actually do the work and only request help for things you don't understand?

[matsp]

You make no effort of:
1. returning anything from CountEvenASCII()
2. printing the number counted in the count function.

--
Mats

[noops]

You are assigning x to 0 every time you call the function.

[mkdl750]

okay i understand.

[mkdl750]

need help with this one

#include <stdio.h>
#include <string.h>

char CountEvenASCII(char str[255], int a, int x);

main()
{
    int num1, num2;
    char w[255];
    num1 = 0;
    printf("Input character string: ");
    scanf("&#37;s", w);
    CountEvenASCII(w, num1, num2);
    printf("\n%d\n\n",w);
    getch();
    return 0;
}

char CountEvenASCII(char str[255], int a, int x)
{
    x=strlen(str);
    if (str[x] % 2 == 0)
    {
        a = (str[x] + a);
    }
    x++;
    CountEvenASCII(str,a,x);
}

[matsp]

Do you actually understand what your own code does?

Do you understand how to solve the problem without recursion (as recursion, at least in this case, is just a way to iterate, we can ignore recursion for the first part of the problem - which is to count the number of even characters. Start by writing a function that does that, then we can work on making it recursive).

--
Mats

[noops]

Now you are setting x to the length of the string each time? Do you realize this makes x++ meaningless?

How does your function know that it is done?

Do you know what a 'base case' is?

[mkdl750]

But i made the code, and a recursive is a function is one that calls itself. Can you proofread it for me? Please?

[matsp]

But i made the code, and a recursive is a function is one that calls itself. Can you proofread it for me? Please?

Yes, a recursive function is one that calls itself, but you don't seem to get what I'm trying to say:
1. You still need to write code that produces the correct result - and it is CLEAR to me that you do not understand the code you have written ("made").
2. My suggestion is to write the code you need to count first, then change that code to make it recursive.
3. We do not do other peoples homework - you are going to school to learn, not to figure out how to copy something.

By the way, as noops suggested, you may want to figure out the base-case (or exit condition) for your recursion - as it currently stands, I don't see any way that your code would even finish execution [that is, assuming the compiler does clever optimization and turns your recursion into an iteration, which any decent compiler should be able to do].

--
Mats