C program to find all occurrence of a character in a string

C – Strings : 

Strings are actually one-dimensional array of characters terminated by a null character ‘\0’. Thus a null-terminated string contains the characters that comprise the string followed by a null.

String is a sequence of characters. char data type is used to represent one single character in C. So if you want to use a string in your program then you can use an array of characters.

The declaration and definition of the string using an array of chars is similar to declaration and definition of an array of any other data type.

Any string ends with a terminating null character ‘\0’. An array definition in such a way should include null character ‘\0’ as the last element.

Here is source code of the C program to find all occurrence of a character in a string. The C program is successfully compiled and run(on Codeblocks) on a Windows system. The program output is also shown in below.

SOURCE CODE : :

/*  C program to find all occurrence of a character in a string  */

#include <stdio.h>

#define MAX_SIZE 100 //Maximum size of the string

int main()
{
    char string[MAX_SIZE];
    char search;
    int i;

    /*
     * Reads a string and character from user
     */
    printf("\nEnter any string: ");
    gets(string);
    printf("\nEnter any character to search: ");
    search = getchar();

    //Runs a loop till the NULL character is found
    for(i=0; string[i]!='\0'; i++)
    {
        /*
         * If character is found in string
         */
        if(string[i] == search)
        {
            printf("\n['%c'] is found at index [ %d ]\n", search, i);
        }
    }

    return 0;
}

Output:

/*  C program to find all occurrence of a character in a string  */

Enter any string: Hello CodezClub

Enter any character to search: C

['C'] is found at index [ 6 ]

['C'] is found at index [ 11 ]

Process returned 0

Above is the source code for C program to find all occurrence of a character in a string which is successfully compiled and run on Windows System.The Output of the program is shown above .