I want to use the variable that is taken from the inputString() method into the countWords() method below, but I unfortunately run into errors when I try using the latter in the main() method. How do I work around this?

import java.util.*;

public class WordCounter {
    public static String inputString(){
        Scanner s = new Scanner(System.in);
        System.out.println("\nInput your desired sentence/string: ");
        String userInput = s.nextLine();
        return userInput;
    }

    public static void countWords(int count, String userInput){

        count = 1;

        for (int i = 0; i < userInput.length() - 1; i++)
        {
            if ((userInput.charAt(i) == ' ') && (userInput.charAt(i + 1) != ' '))
            {
                count++;
            }
        }
        System.out.print("Number of words in the sentence/string: " + count);    
    }

    public static void main (String [] args){
        System.out.println("Word Counter.");
        inputString();
        countWords();
    }
}

>Solution :

Learn to return values, and pass values

1. Capture the return value coming from your inputString method.
2. Pass that returned value to your countWords method.

Change this:

inputString();
countWords();

… to this:

String input = inputString();  // Capture the return value.
countWords( input );           // Pass the captured value.

And it looks like count in countWords is supposed to be the result. So that should be returned to the calling method.

String input = WordCounter.inputString();
int count = WordCounter.countWords( input );

And alter your countWords to return that value. Change the declared return type from void to int. Add a return line at the end.

public static int countWords( String userInput ){
    … 
    return count ;  
}

OOP

Looking at the bigger picture, try to avoid static as a student learning object-oriented programming.

Create multiple classes, where each class has one main responsibility. If we look at your business problem, we have three responsibilities:

• Business logic: Analyzing text to count words.
• User interface: Interacting with user on the console.
• An app to run the show, with its main method.

You might start with three classes.

First, the business logic.

package work.basil.example.wordcounter;

import java.util.concurrent.ThreadLocalRandom;

// Takes a string, analyzes to determine a count of words, and returns that count.
public class WordCounter
{
    private CharSequence text;

    public WordCounter ( final CharSequence input )
    {
        this.text = input;
    }

    public int wordCount ( )
    {
        return ThreadLocalRandom.current().nextInt( 0 , 10 ); // Fake method. Put your code here.
    }

    public CharSequence text ( )
    {
        return this.text;
    }
}

The console input manager.

package work.basil.example.wordcounter;

public class ConsoleInputGatherer
{
    public String gatherInput ( )
    {
        // Fake method. Write your code here.
        return "your text goes here.";
    }
}

And the main app.

package work.basil.example.wordcounter;

public class App
{
    public static void main ( String[] args )
    {
        App app = new App();
        app.demo();
    }

    private void demo ( )
    {
        String input = new ConsoleInputGatherer().gatherInput();
        int count = new WordCounter( input ).wordCount();

        // Report results.
        System.out.println( "Input: " );
        System.out.println( input );
        System.out.println( "… has a word count of: " + count );
    }
}

When run:

Input: 
your text goes here.
… has a word count of: 3

Avoid char

And, by the way, the char type has been essentially broken since Java 2, and legacy since Java 5. As a 16-bit value, it is physically incapable of representing most characters. Instead, to work with individual characters, use code point integer numbers.