there is an error in the language C code but I can't figure out where it is

Question

the goal of this code is to display the frequency or how much each letter are being use in the input but as I click compile there are an erroe show that

main.c:50:19: error: invalid operands to binary * (have 'float *' and 'int')"
    avg = freq*100/count;

Code

#include <stdio.h>
#include <ctype.h>
#include <float.h>

int main()
{
    char alp;
    float count, i, avg;
    float freq[26];


    printf("Enter the alphabet : ");
    scanf("%c", &alp);
    do{
        printf("Enter the alphabet : ");
        scanf("%c", &alp);

        switch(alp) {
            case 'a' :freq[0]++; break;
            case 'b' :freq[1]++; break;
            case 'c' :freq[2]++; break;
            case 'd' :freq[3]++; break;
            case 'e' :freq[4]++; break;
            case 'f' :freq[5]++; break;
            case 'g' :freq[6]++; break;
            case 'h' :freq[7]++; break;
            case 'i' :freq[8]++; break;
            case 'j' :freq[9]++; break;
            case 'k' :freq[10]++; break;
            case 'l' :freq[11]++; break;
            case 'm' :freq[12]++; break;
            case 'n' :freq[13]++; break;
            case 'o' :freq[14]++; break;
            case 'p' :freq[15]++; break;
            case 'q' :freq[16]++; break;
            case 'r' :freq[17]++; break;
            case 's' :freq[18]++; break;
            case 't' :freq[19]++; break;
            case 'u' :freq[20]++; break;
            case 'v' :freq[21]++; break;
            case 'w' :freq[22]++; break;
            case 'x' :freq[23]++; break;
            case 'y' :freq[24]++; break;
            case 'z' :freq[25]++; break;
            default :;}
        count++;
    }while (alp==-1);

    for( i = 0; i < 26; i = i + 1 ){
        avg = freq*100/count;
        printf("%c : %f", i+65, avg);

    }


    return 0;
}

by the way I'm not a computer science student so if I make a stupid mistake please don't judge me.

Doesn't that error message tell you *exactly* where the error is? line 50 of your source file? — WhozCraig, May 12 '17 at 16:14
@RoiHatam think that's a formatting issue with the question - it's line 50 — Chris Turner, May 12 '17 at 16:15
You might also find it helpful to refer to [this question](http://stackoverflow.com/questions/5240789/scanf-leaves-the-new-line-char-in-buffer) about the use of `scanf`. — Weather Vane, May 12 '17 at 16:17
Also, please note that the array `freq[]` is *uninitialised*. — Weather Vane, May 12 '17 at 16:19
Unrelated to your problem: don't you think you can reduce the whole switch statement including the 26 cases to one single line? No need to be a CS student for this BTW. — Jabberwocky, May 12 '17 at 16:38
@MichaelWalz A worthy challenge either way, particularly for [non contiguous letter encodings](https://en.wikipedia.org/wiki/EBCDIC). Of course, only old-time CS students would think of such things (yeah, just dated myself). — WhozCraig, May 12 '17 at 16:50
@WhozCraig OK, with non contiguous encoding you can probably cut it down to 4-5 lines. — Jabberwocky, May 13 '17 at 18:50
@MichaelWalz a counting array, `unsigned count[1U << CHAR_BIT]` makes short work of it regardless, and portably at that. — WhozCraig, May 13 '17 at 18:55

score 1 · Answer 1 · answered May 12 '17 at 16:14

1

You have this code...

avg = freq*100/count;

...freq is an array so it should be

avg = freq[i]*100/count;

answered May 12 '17 at 16:14

Chris Turner

8,082
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score 1 · Answer 2 · answered May 12 '17 at 16:16

1

You are missing the array index in the following line:

avg = freq*100/count;

It should be:

avg = freq[i]*100/count;

Array pointer cannot be multiplied :)

answered May 12 '17 at 16:16

Liran Funaro

2,750
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score 1 · Answer 3 · answered May 12 '17 at 16:17

1

here freq is array of float numbers. array name is a pointer to memory location of first position i.e. freq points to freq[0].

therefore when you use "avg = freq*100/count;" the freq is (float*) and it expects float. so use freq[i]

answered May 12 '17 at 16:17

mangupt

369
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Riccardo Bonafede · Answer 4 · 2017-05-12T16:41:41.347

0

There are multiple errors in this code: 1) you use unitializated vars:

float count=0, avg=0;

2) avg is an array

 avg = freq[i]*100/count;

3)i is a float, but you want a integer (or just a char)

char i=0;

4) while(apl==-1) is not correct, the do while will always terminated(excep when there will be an error. use

while(apl!=-1)

edited May 12 '17 at 16:41

answered May 12 '17 at 16:21

Riccardo Bonafede

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the code can be run but the number that shows the frequency are display strangely Ex: enter the alphabeth:werfgyyjjjjkkklpo but the number still display as zero – Mizery 26 May 12 '17 at 16:35
there is another error: while (alp==-1); i think you would like to have while(alp != -1) – Riccardo Bonafede May 12 '17 at 16:40

there is an error in the language C code but I can't figure out where it is

4 Answers4