C function input string and calculation

Question

    #include <stdio.h>
    #include <string.h>
    #define SIZE 30
    int countWord(int a[]);
    int countSpace(int a[]);
    int countVowel(int a[]);
    int printResult(int a[]);

int main()//starting main 
{
    char string1[SIZE];
    printf("%s","Enter a string less than 29 characters");
    scanf("%29[^\n]",string1);  //anything except \n.

    printResult(string1);
}
int countWord(int a[]){
    int count=1;
    for(size_t i=0;i<SIZE&&a[i]!='\0';++i){ 
        if(a[i]==' '){
            count++;
        }
    }
    return count;
}
int countSpace(int a[]){
    int count1=0;
    for(size_t i=0;i<SIZE&&a[i]!='\0';++i){ 
        if(a[i]==' '){
            count1++;
        }
    }
    return count1;
}
int countVowel(int a[]){
    int count2=0;
     for(size_t i=0;i<SIZE&&a[i]!='\0';++i){
         if(strchr("aeiouAEIOU", a[i])){
            count2++;
        }
     }
     return count2;
}
int countNum(int a[]){
    int count3=countWord(a)-countVowel(a)-countSpace(a);
    return count3;
}
int printResult(int a[]){
    printf("Your sentence include\n");
    printf("Number of words:%d\n",countWord(a));
    printf("Number of spaces:%d\n",countSpace(a));
    printf("Number of vowels:%d\n",countVowel(a));
    printf("Number of consonants and special characters:%d\n",countNum(a));
}

this program is about asking user to input a string and calculate how many words,space,vowels... but I get very wrong result after the enter a string. I thought the logic is fine and was struggling to find any issues here

Answer 1

struggling to find any issues here

Save time, enable all warnings. That is the key mistake.

Review types.

int printResult(int a[]);

  char string1[SIZE]; 
  printResult(string1);

---

Word count errors with " ", " abc def ", " abcd".

Alternative: set a flag for the start of a word.

int countWord(int a[]){
int countWord(const int_but_I_suspect_you_want *a) {
  int count=0;
  int start_of_word_possible = 1;
  while (*a) {
    if (isspace(*a)) {
      start_of_word_possible = 1;
    } else {
      if (start_of_word) count++;
      start_of_word_possible = 0;
    }
    a++;
  }
  return count;
}

Answer 2

Without knowing the original string you entered, it is not possible to know what unexpected result you saw, but here are general suggestions:

• Since you are working with strings, it would be more idiomatic to exchange int a[] for const char *a in all of your function prototypes and functions.
• Comment the phrase anything except \n. after the scanf call in main.
• If you are not going to return a value in int printResult(const char *a, make it void printResult(const char *a.
• The minimum signature for main is int main(void){...return 0;}.

With only these changes, and upon entering This is a string, I get this result:

Number of words:4
Number of spaces:3
Number of vowels:4
Number of consonants and special characters:-3

Because 4 - 3 - 4 == -3, it appears all the values were calculated correctly.

Code updated per my comments above:

int main(void)//starting main 
{
    char string1[SIZE];
    printf("%s","Enter a string less than 29 characters");
    scanf("%29[^\n]",string1);//anything except \n.

    printResult(string1);

    return 0;
}
int countWord(const char *a){
    int count=1;
    for(size_t i=0;i<SIZE&&a[i]!='\0';++i){ 
        if(a[i]==' '){
            count++;
        }
    }
    return count;
}
int countSpace(const char *a){
    int count1=0;
    for(size_t i=0;i<SIZE&&a[i]!='\0';++i){ 
        if(a[i]==' '){
            count1++;
        }
    }
    return count1;
}
int countVowel(const char *a){
    int count2=0;
     for(size_t i=0;i<SIZE&&a[i]!='\0';++i){
         if(strchr("aeiouAEIOU", a[i])){
            count2++;
        }
     }
     return count2;
}
int countNum(const char *a){
    int count3=countWord(a)-countVowel(a)-countSpace(a);
    return count3;
}
void printResult(const char *a){
    printf("Your sentence include\n");
    printf("Number of words:%d\n",countWord(a));
    printf("Number of spaces:%d\n",countSpace(a));
    printf("Number of vowels:%d\n",countVowel(a));
    printf("Number of consonants and special characters:%d\n",countNum(a));

}