Question

using java create hash set that can

(a) Read one word from the file. (b) Remove all non-alphanumeric characters from the word. A non-alphanumeric character is any character other than the lowercase and uppercase English letters, and the numerals 0 through 9. (c) Add the modified word to the hash set.

for the file use a txt file: Hi my name is rick.

Answer 1

Program: In this program, we read a text file from the system, read each word of each line, check if a word contains any non-alphanumeric characters, if it does then we remove it from the word and add it to the hash set. At the end, we print our hash Set to check our program.

Note: HashSeet contains elements in random order, for sorted order we can use a TreeSet,

Code:

import java.io.File;
import java.io.FileNotFoundException;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class CreateHash {

    public static void main(String[] args) {
        //Create a hash set
        Set<String> wordSet = new HashSet<>();

        //Create File class instance, pass name of text file as input
        File file = new File("input.txt");

        //Use a try catch block to catch File not found exception
        try {
            //Read the file, pass file instance as input to scanner class object
            Scanner read = new Scanner(file);

            //Read each line of the text file
            while (read.hasNextLine()) {

                //Store the current line
                String line = read.nextLine();

                //Create an array of words in the current line, by splitting the line using space as delimiter
                String[] words = line.split(" ");

                //Read each word
                for (String word : words) {

                    //Create a loop till the length of word
                    for (int i = 0; i < word.length(); i++) {

                        //Store current character
                        char curr = word.charAt(i);

                        //Check if its alphanumeric or not
                        if (!Character.isLetterOrDigit(curr)) {

                            //If it is not, remove current character from the word using substring function
                            word = word.substring(0, i) + word.substring(i + 1);

                            //decrement the index as length of string has reduced,
                            //there might be continuous non-alphanumeric characters
                            i--;
                        }
                    }

                    //After operating the word, add it to the set
                    wordSet.add(word);

                }
            }
            read.close();

            //Print the set of words
            System.out.println(wordSet);

        } catch (FileNotFoundException e) {
            System.out.println("File not found");
        }
    }
}

2 3 Fimport java.io.File; import java.io.FileNotFoundException; import java.util.HashSet; import java.util.Scanner; import java.util.Set; public class CreateHash { 7 8 9 10 public static void main(String[] args) { //Create a hash set Set<String> wordSet = new HashSets>(); 11 //Create File class instance, pass name of text file as input File file = new File( pathname: "input.txt"); 12 13 14 15 16 17 18 19 20 21 22 23 //Use a try catch block to catch File not found exception try { //Read the file, pass file instance as input to scanner class object Scanner read = new Scanner(file); //Read each line of the text file while (read.hasNextLine() { 24 25 //Store the current line String line = read.nextLine(); //Create an array of words in the current line, by splitting the line using space as delimiter String[] words = line.split( regex:""); 26 27 28 29 30 31 32 33 34 //Read each word for (String word: words) { //Create a loop till the length of word for (int i = 0; i < word.length(); i++) { 35 36 //Store current character char curr = word.charAt(i); 37 38 39 //Check if its alphanumeric or not if (!Character.isLetterOrDigit(curr)) { 140 41 42 //If it is not, remove current character from the word using substring function word = word.substring(@, i) + word.substring(i + 1); 43 44 45 //decrement the index as length of string has reduced,

46 //there might be continuous non-alphanumeric characters i--; 48 A 49 50 51 52 53 //After operating the word, add it to the set wordSet.add(word); } 54 55 56 read.close(); 57 58 //Print the set of words System.out.println(wordSet); 59 60 61 } catch (FileNotFoundException e) { System.out.println("File not found"); 162 163 164 } 65

Text File (input.txt):

Hi my name is rick.

Output:

[Hi, name, is, rick, my] Process finished with exit code o