Question

Suppose you are given a file containing a list of names and phone numbers in the form "First_Last_Phone."

Write a program to extract the phone numbers and store them in the output file.

Example input/output:

Enter the file name: input_names.txt

Output file name: phone_input_names.txt

1) Name your program phone_numbers.c

2) The output file name should be the same name but an added phone_ at the beginning. Assume the input file name is no more than 100 characters. Assume the length of each line in the input file is no more than 10000 characters.

3) The program should include the following function: void extract_phone(char *input, char *phone); The function expects input to point to a string containing a line in the “First_Last_Phone” form. In the function, you will find and store the phone number in string phone.

Comments would be helpful as well Thanks

Answer 1

/ Java program to read all mobile numbers

// present in given file

import java.util.regex.*;

import java.io.*;

class MobileNumberExtraction

{

    public static void main(String[] args) throws IOException

    {

        // Write Mobile Numbers to output.txt file

        PrintWriter pw = new PrintWriter("output.txt");

        // Regular expression for mobile number

        Pattern p = Pattern.compile("(0/91)?[7-9][0-9]{9}");

        // BufferedReader for reading from input.txt file

        BufferedReader br = new BufferedReader

                                (new FileReader("input.txt"));

        String line = br.readLine();

         

        while (line != null)

        {

            Matcher m = p.matcher(line);

            while (m.find())

            {

                // Write the mobile number to output.txt file

                pw.println(m.group());

            }

            line = br.readLine();

        }

        pw.flush();

    }

}