Question

Write a java program to read a string from the keyboard, and count number of digits, letters, and whitespaces on the entered string. You should name this project as Lab5B.

• This program asks user to enter string which contains following characters: letters or digits, or whitespaces. The length of the string should be more than 8. You should use nextLine() method to read string from keyboard.

• You need to extract each character, and check whether the character is a letter or digit or whitespace.

• You can access character at a specific index using charAt() method. Once you have extracted the character, you can test the extracted character using character test methods.

• You can look at google/web search to check the methods (isDigit, isLetter, and isSpaceChar) available to test a character. Use the syntax properly in your code.

• Once you found a match, simply increase the value of the counter by 1. You need 3

  separate counters to count letters, digits, and spaces.

• In this program, you do not need to worry about uppercase or lowercase letter.

     Sample Output 1
  

     Enter the string: EEEEEEE RRR LLLLLL UUUUUUUUUU
     Number of spaces: 3
     Number of letters: 26
     Number of digits: 0
  

Answer 1

import java.util.*;// util package is used for using Scanner class

class Lab5B {
        public static void main (String[] args) {
                String str;// variable to store string entered
                int d_count=0,l_count=0,s_count=0,len;//variables for digit count,letter count,space count and length 
                Scanner s= new Scanner(System.in);//used to read string from keyboard
                System.out.println("Enter the string");
                str=s.nextLine(); // Reading the string
                len=str.length(); // Calculating the length of the string
                if(len<=8)// if length of string is less than or equal to 8 then this message is printed
                System.out.println("Enter the string with length more than 8");
                else// if length of string is more than 8 else is executed
                {
                    for(int i=0;i<len;i++)// loop iterates from index 0 to length of string
                    {
                       char c=str.charAt(i); // extracting the character present at ith index
                        if(Character.isLetter(c))// isLetter is used to determine whether the character is alphabet or not 
                        l_count++;// incrementing letters count 
                        else if(Character.isDigit(c))//isDigit is used to determine whether the character is digit or not
                        d_count++;//if it is digit then digit count is incremented
                        else if(Character.isSpaceChar(c))//isSpaceChar is used to determine whether the character is space(" ") or not
                        s_count++;// if space then incrementing the space count
                    }
                    System.out.println("Number of spaces: "+s_count);
                    System.out.println("Number of letters: "+l_count);
                    System.out.println("Number of digits: "+d_count);
        }
        }
}

Please comment if you have any doubts.

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