Question

Use Java to answer the question

(Occurrences of a specified character)

Write a method that finds the number of occurrences of a special character in a string using the following header:

public static int count (String str, char a)

For example, count("Welcome", 'e') returns 2. Write a test program that prompts the user to enter a string followed by a character then displays the number of occurrences of the character in the string.

In addition to the requirements described in the exercised, your solution must meet the following requirements:

• Your method must match the method header (and signature) exactly (including parameter names)
• Your method must not have any input or output --
  e.g. you may not read the input from the keyboard or output to the screen from within your method.
• All input and output must occur in the main method of your program and pass the values to your method and use the return value to get the result for output. (See below)
• The variable names you use for input and output must be different than the parameter names for your method (e.g. str and a)
• Case matters, so your method should distinguish between counting 'b' vs. 'B'.
• You must have a validation loop for each of the input string and the character. Empty strings are the only invalid inputs

Answer 1

String_counting.java

import java.util.*;
class String_counting{
   public static int count (String str, char a){
      
       int c=0;
       int len = str.length();
       for(int i=0;i<len;i++){
           if(str.charAt(i)==a){
               c++;
           }
       }
       return c;
   }
   public static void main(String[] args) {
       Scanner scan = new Scanner(System.in);
       String stri;
       System.out.println("Enter a string:");
       stri = scan.nextLine();
       //Below while loop for checking the entered string is empty or not if the string is empty than it will run upto user enter a string
       while(stri.equals(null) || stri.equals("")){
           System.out.println("Invalid input,Please Enter correct string:");
           stri = scan.nextLine();
       }
      
       char c;
       System.out.println("Enter a character:");
       c = scan.next().charAt(0);
       while(c==' ')
       {
           System.out.println("Enter a character:");
           c = scan.next().charAt(0);
       }
       System.out.println("Given Character count in the given string is: "+count(stri,c));
       //count(stri,c);
   }
}