Program to Count Number of Words in a Given String and File

We can easily count number of words in a given string or file to search the space between the words. In this article, I will write a program to count number of words
in a given string and file.

Steps to count number of words

1. Pass the string as input.
2. Using while loop searches the empty space in a given string.
3. If you found space, set the flag true.
4. If the flag is true then increment word counter by 1.

See the below code,

In the below code, I am executing while loop until not getting the null character of the given string. In this loop, I am searching space between the word in a given string and if I will find the space then make the flag true.

If the flag is true and the next character is not empty, then increment the word counter.

#define TRUE   0
#define FALSE  1


unsigned wordCounter(char *PString)
{
    int flag = TRUE;

    unsigned int wCounter = 0; // word counter

    // Runt untill not get null
    while (*PString)
    {
        //Set the flag true if you got the space
        if (*PString == ' ')
        {
            flag = TRUE;
        }
        else if (flag == TRUE) //if next word is not empty and flag is true,
        {
            //increment word counter
            flag = FALSE;
            ++wCounter;
        }

        // Move to next character
        ++PString;
    }

    return wCounter;
}

If you love online courses, then here is a good c language course for you from the Pluralsight, 10 days trial is Free.

C Program to Count Number of Words in a given string

In this example code, I am counting the word in a given string using the above-described function followed by described steps. You can see the string”Welcome to aticleworld”, it contains three words.

#include <stdio.h>

#define TRUE   0
#define FALSE  1


unsigned wordCounter(char *PString)
{
    int flag = TRUE;

    unsigned int wCounter = 0; // word counter

    // Run until not get null character
    while (*PString)
    {
        //Set the flag true if you got the space
        if (*PString == ' ')
        {
            flag = TRUE;
        }
        else if (flag == TRUE) //if next word is not empty and flag is true,
        {
            //increment word counter
            flag = FALSE;
            ++wCounter;
        }

        // Move to next character
        ++PString;
    }

    return wCounter;
}


int main(void)
{
    char *pMsg = "Welcome to aticleworld"; //string

    unsigned int count = 0;

    count = wordCounter(pMsg); //function count the words

    printf("No of words : %u",count);


    return 0;
}

C Program to Count Number of Words in a given file

In this example code, I am creating a text file “Info.txt” and writing into the string “Welcome to aticleworld”. When the file has been created successfully then open the file in reading mode and read all the string which has been written into the file at the time of the file creation.

Store all the read data into the buffer and use the function (wordCounter) to count the number of words.

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

#define TRUE   0
#define FALSE  1


//create file and write data
int createFile(char *pFileData)
{
    FILE *fpInfo = NULL;
    int len = 0;

    fpInfo = fopen("Info.txt", "w");//create file in write mode
    if(fpInfo== NULL)
        return 1;

    len = strlen(pFileData);

    fwrite(pFileData, 1, (len+1), fpInfo);//write data into the file
    fclose(fpInfo);//close the file

    fpInfo = NULL;

    return 0;
}


//read file data
int readFileData(char *pReadFileData)
{
    FILE *fpInfo = NULL;
    int len = 0;
    int data = 0;

    fpInfo = fopen("Info.txt", "r"); //open file in read mode
    if(fpInfo== NULL)
        return 1;

    while ((data = getc(fpInfo)) != EOF)//read file data till EOF
    {
        *pReadFileData++ = data;
    }

    fclose(fpInfo);//close the file
    fpInfo = NULL;

    return 0;
}


//count the word
unsigned wordCounter(char *PString)
{
    int flag = TRUE;

    unsigned int wCounter = 0; // word counter

    // Runt untill not get null
    while (*PString)
    {
        //Set the flag true if you got the space
        if (*PString == ' ')
        {
            flag = TRUE;
        }
        else if (flag == TRUE) //if next word is not empty and flag is true,
        {
            //increment word counter
            flag = FALSE;
            ++wCounter;
        }

        // Move to next character
        ++PString;
    }

    return wCounter;
}

int main(int argc, char *argv[])
{

    char *pMsg = "Welcome to aticleworld"; //Msg
    int status = 0;
    char fileData[256] = {0};
    unsigned int count = 0;

    status = createFile(pMsg); //create the file and write string
    if(status== 1)
        return 1;


    status = readFileData(fileData); //read file data
    if(status== 1)
        return 1;

    printf("Data Read from file : %s\n",fileData);

    count = wordCounter(fileData); //count words

    printf("No of words : %u\n",count);


    return 0;
}

Output:

Data Read from file : Welcome to aticleworld
No of words : 3