Question

Write a Java Program that performs the following functionalities: and you can use if statements, cases, and string methods

Enter a new main sentence

Find a String

Find all incidents of a String

Find and Replace a String

Replace all the incidents of a String

Count the number of words

Count a letter’s occurrences

Count the total number of letters

Delete all the occurrences of a word

Exit

The program will display a menu with each option above, and then ask the user to enter their choice. There should also be a tenth option (option J) to quit, in which case, the program will simply display a goodbye message.

Based on the user’s choice, the program will perform the chosen functionality - more details are given below for each one. Make sure to include proper output for all cases (such as instructions, questions to the user, or directions telling the user to input something specific). Make sure the menu uses letters not numbers!

Note: The program should keep running and displaying the menu after each functionality, until the user chooses to exit! Make sure to get a default sentence from the user before going into the menu options.

Descriptions of Each Option:

Enter a new main sentence: Ask the user to input a new sentence. This sentence will be later on used in the other menu operations ex: (Find a String, Find all incidents of a String, etc.)

Find a String: Ask the user to input a word, then display the index of the first occurrence of the word in the main sentence. If the word is not found make sure to output the word is not found!

TIP: If you get a runtime error because the word is not found, then your if statement structure is incorrect!

Find all incidents of a String: Ask the user to input a word, then display the index of every occurrence of that word in the main sentence. If the word is not found make sure to output the word is not found!

Find and Replace a String: Prompt the user to input a word, then ask the user to input another new word for replacement. Lastly, locate the word in the main sentence and replace it with the new word. If the user inputs a string that’s not found in the main sentence make sure to output the word is not found.
Note: This option only replaces the first occurence of the String.

Replace all incidents of a String: Prompt the user to input a word, then ask the user to input another new word for replacement. Lastly, locate the all the occurrences of the word in the main sentence and replace all of them with the new word. If the user inputs a string that’s not found in the main sentence make sure to output the word is not found.

Count the number of words: Display the number of words in the main sentence.
TIP: Think of what usually separates words and just count the number of occurrences for that.

Count a letter’s occurrences: Prompt the user to enter a letter. Store that letter in a char variable and then display how many times the char occurs in the main sentence.

Count the total number of letters: Store the main sentence in a temporary variable, try to trim it from spaces. Then use the length method to count how many letters/characters there are in the main sentence.

Delete all the occurrences of a word: Prompt the user to enter a word, then delete all the occurrences of that word in the main sentence then display the updated main sentence.

Note: If the user types “at”, then all occurrences of “at” should be removed. Example: “station” becomes “stion”. On the other hand, if the user types “ at ” with spaces then “station” is not altered.

Exit: Simply display a goodbye message. End the program.

Answer 1

****This requires a lot of effort so please drop a like if you are satisfied with the solution****

I have satisfied all the requirements of the question and I'm providing the screenshots of code and output for your reference..

Code:

import java.util.Scanner;
public class Main
{
   public static void main(String[] args) {
       Scanner in=new Scanner(System.in);
       char choice;
       String mainString="";
       while(true){
       System.out.println("\na. Enter a new main sentence");
       System.out.println("b. Find a string");
       System.out.println("c. Find all incidents of a string");
       System.out.println("d. Find and Replace a string");
       System.out.println("e. Replace all the incidents of a string");
       System.out.println("f. Count the number of words");
       System.out.println("g. Count a letter's occurences");
       System.out.println("h. Count the total number of letters");
       System.out.println("i. Delete all occurences of a word");
       System.out.println("j. Exit");
       System.out.print("\nchoice => ");
       choice=in.next().charAt(0);
       System.out.println();
       in.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
       if(choice=='a'){
       System.out.print("Enter the main sentence: ");
       mainString=in.nextLine();
       }
       if(choice=='b'){
       System.out.print("Enter a word to search: ");
       String word1=in.nextLine();
       if(mainString.indexOf(word1)!=-1){
       System.out.println("The word "+word1+" is found in the main sentence at "+mainString.indexOf(word1));
       }
       else{
       System.out.println("Word not found!");
       }
       }
       if(choice=='c'){
       int index=0;
       System.out.print("Enter a word to search: ");
       String word2=in.nextLine();
       if(mainString.indexOf(word2)!=-1){
       System.out.print("The word is found at indexes: ");
while(index != -1){
index = mainString.indexOf(word2, index);
if (index != -1) {
System.out.print(index+" ");
index++;
}
}
       }
       else{
       System.out.println("Word not found!");
       }
       }
       if(choice=='d'){
       System.out.println("Enter word to replace: ");
       String word3=in.nextLine();
       if(mainString.indexOf(word3)!=-1){
       System.out.println("Enter new word: ");
       String newWord=in.nextLine();
       mainString=mainString.replaceFirst(word3,newWord);
       System.out.println("The string after replacing: "+mainString);
       }
       else{
       System.out.println("Word not found!");
       }
       }
       if(choice=='e'){
       System.out.println("Enter word to replace: ");
       String word4=in.nextLine();
       if(mainString.indexOf(word4)!=-1){
       System.out.println("Enter new word: ");
       String word5=in.nextLine();
       mainString=mainString.replaceAll(word4,word5);
       System.out.println("The string after replacing: "+mainString);
       }
       else{
       System.out.println("Word not found!");
       }
       }
       if(choice=='f'){
       int count = 1;
       for (int i = 0; i < mainString.length() - 1; i++)
       {
           if ((mainString.charAt(i) == ' ') && (mainString.charAt(i + 1) != ' '))
           {
               count++;
           }
       }
        System.out.println("Number of words in main string = " + count);
       }
       if(choice=='g'){
       System.out.print("Enter a letter to count: ");
       char c=in.next().charAt(0);
       int j=0;
       for(int i=0;i<mainString.length();i++){
       if(mainString.charAt(i)==c)
       j++;
       }
       System.out.println("Number of occurences of letter "+c+" is: "+j);
       }
       if(choice=='h'){
       int counter = 0;
for (int i = 0; i < mainString.length(); i++) {
if (Character.isLetter(mainString.charAt(i)))
counter++;
}
System.out.println("Main string has "+counter + " letters.");
       }
       if(choice=='i'){
       System.out.print("Enter a word to delete from main string: ");
       String word5=in.nextLine();
       mainString = mainString.replaceAll("(?i)\\b" + word5 + "\\b *", "").trim();
       System.out.println("The string after deleting "+word5+" is: "+mainString);
       }
       if(choice=='j'){
       System.out.println("Good Bye!");
       break;
       }
       }
   }
}

output Screenshots:

Code Screenshots: