C program to search all occurrences of a word in given string

Write a C program to search all occurrences of a word in given string using loop. How to find index of all occurrences of a word in given string using loop in C programming. Logic to search all occurrences of a word in given string.

Example

Input

Input string: I love programming. I love Codeforwin.
Input word to search: love

Output

'love' is found at index: 2
'love' is found at index: 22 

Required knowledge

Basic C programming, Loop, String

Must know -

Program to search occurrences of a word in string

/**
 * C program to find last occurrence of a word in given string
 */

#include <stdio.h>
#include <string.h>
#define MAX_SIZE 100 // Maximum string size

int main()
{
    char str[MAX_SIZE];
    char word[MAX_SIZE];
    int i, j, found;
    int strLen, wordLen;

    /* Input string and word from user */
    printf("Enter any string: ");
    gets(str);
    printf("Enter any word to search: ");
    gets(word);

    strLen  = strlen(str);  // Find length of string
    wordLen = strlen(word); // Find length of word


    /*
     * Run a loop from starting index of string to
     * length of string - word length
     */
    for(i=0; i<strLen - wordLen; i++)
    {
        // Match word at current position
        found = 1;
        for(j=0; j<wordLen; j++)
        {
            // If word is not matched
            if(str[i + j] != word[j])
            {
                found = 0;
                break;
            }
        }

        // If word have been found then print found message
        if(found == 1)
        {
            printf("'%s' found at index: %d \n", word, i);
        }
    }

    return 0;
}

Output

Enter any string: I love programming. I love Codeforwin. I love Computers.
Enter any word to search: love
'love' found at index: 2
'love' found at index: 22
'love' found at index: 41

Happy coding 😉

About Pankaj

Pankaj Prakash is the founder, editor and blogger at Codeforwin. He loves to learn new techs and write programming articles especially for beginners. He works at Vasudhaika Software Sols. as a Software Design Engineer and manages Codeforwin. In short Pankaj is Web developer, Blogger, Learner, Tech and Music lover.

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