How to recognise Longest Alphabetic word in an array of strings in Java? (any substring without symbols or numbers)

jonakru :

I am new to Java and I need to solve an exercise that requires the following:

For a string that the user inputs, return the largest word (so far so good here)

But, it should take into account that numbers and symbols are not words.

For example: Hello, my name is Jonathan and my phone is 0123456789 should return "Jonathan" as longest word.

Example 2: H3llo W0rld, Java 1s fun!, should return "Java" as longest word.

In my pseudo-code I thought about the following:
A) Request input from user.
B) While input invalid, loop.
C) Scan the input
D) Separate the words by the spaces, or tokens.
E) If Word contains just letters A-Z && a-z do the following code:
e1) Check for longest word, with a for.
e2) Print result
F) else if: move to the next word.

Here is the code that I have so far. As you see, many parts are taken from here and adapted to the code. The "Find the longest in array" is a popular subject, yet I am not able to do the checking for the alphabetical characters. Any help will be welcomed.

The problem is that I don't know how to implement the part that checks for letters.

Code:

package longestword;

import java.util.Scanner;

public class LongestWord {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a String: ");

        //looping for non empty strings
        int largestLength = 0;
        String largestWord = "";
        String userinput = sc.nextLine();
        while (userinput.equals("")) {
            System.out.println("Please insert a String: ");
            userinput = sc.nextLine();
        }

        for (String b : userinput.split(" ")) {
            if (largestWord.length() == 0) {
                largestLength = b.length();
                largestWord = b;
            } else if (b.length() >= largestLength) {
                largestLength = b.length();
                largestWord = b;
            }
        }
        sc.close();
        System.out.println("Longest Word: " + largestWord);

    }

    public boolean isAlpha(String userinput) {
        char[] chars = userinput.toCharArray();

        for (char c : chars) {
            if (!Character.isLetter(c)) {
                return false;
            }
        }
        return true;
    }
}
/*

     char c = '*';

        if( (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
            System.out.println(c + " is an alphabet.");
        else
            System.out.println(c + " is not an alphabet.");
    }
}
*/

Eran :

Just change your isAlpha method to static and use it as follows:

for (String b : userinput.split(" ")) {
    if (isAlpha(b)) {
        if (largestWord.length() == 0) {
            largestLength = b.length();
            largestWord = b;
        } else if (b.length() >= largestLength) {
            largestLength = b.length();
            largestWord = b;
        }
    }
}