Java：接受字符串对象作为参数并返回字数的写入方法

Question

The assignment for java is to write a method that accepts string objects as an argument and returns the number of words it contains. Demonstrate the method in a program that asks the user to input a string and passes it to the method. The number of words should be displayed in the screen. I know its close but there are probably some errors.

public class WordCounter
{

    //Asks and gets the users input here
    private static string getInput(Scanner in)
    {
        String input;

        //Imported scanner here
        Scanner in = new Scanner(System.in);

        //Ask the user to enter string here
        System.out.println("Enter a string here: ");
        input = in.nextLine();

        //Create an if/else statment to find out if the user entered input
        if(input.length() > 0)
        {
            getInput(input);    //Get word count
        }
        else
        {
            System.out.println("Error -- You must enter a string!");
            System.out.println("Enter a string here: ");
            input = in.nextLine();
        }

        return input;

    }   //Close public static string getInput here



    //Calculates the number of words the user inputs
    public static int getWordCount(String input)
    {
        String[] result = input.split(" ");

        return result.length;

    }   //Close public static int getWordCount here     



    //Prints out the number of words from the users input in string above
    public static void main(String[] args)
    {

        //Print out the number of words within the users string here
        System.out.println("The number of words in the string are: " + counter);

    }   //Close public static void main string args here

Answer 1

First, you need to clean up your getInput() method -

private static String getInput(Scanner in) {
  // Ask the user to enter string here
  do {
    System.out.println("Enter a string here: ");
    String input = in.nextLine();

    // Create an if/else statement to find out if the user
    // entered input
    if (input.trim().length() > 0) {
      return input.trim();
    } else {
      System.out.println("Error -- "
          + "You must enter a string!");
    }
  } while (true);
} // Close public static string getInput here

Second, in your main method - declare and initialize your counter -

int counter = getWordCount(getInput(new Scanner(System.in)));

Then your code worked for me.

Answer 2

I fixed quite a few parts of you code, and commented where I changed something.

import java.util.Scanner;

public class WordCounter
{
//Asks and gets the users input here
private static String getInput(Scanner in) // java is CASE-SENSITIVE. string !=String
{
    String input;

    //Imported scanner here
    // Scanner in = new Scanner(System.in); // cannot redefine variable in same scope, also un-needed
    //Ask the user to enter string here
    System.out.println("Enter a string here: ");
    input = in.nextLine();

    //Create an if/else statment to find out if the user entered input
    if(input.isEmpty()) // better form to do this
    {
        System.out.println("Error -- You must enter a string!");
       return getInput(in);    //Get input again (it's bad form to use recursion here, but not technically wrong)
    }
    else
    {
        return input;
    }
}   //Close public static string getInput here



//Calculates the number of words the user inputs
private static int getWordCount(String input)
{
    String[] result = input.split(" ");
    return result.length;
}   //Close public static int getWordCount here     



//Prints out the number of words from the users input in string above
public static void main(String[] args)
{
    //Print out the number of words within the users string here
    String input = getInput(new Scanner(System.in)); //You needed to actually call these methods!
    int counter = getWordCount(input);
    System.out.println("The number of words in the string are: " + counter);
}   //Close public static void main string args here

}

Answer 3

Where is "counter" declared? Where is the rest of your code? You declare your methods but don't call them. Also within your first if statement I believe you meant to call getWordCount(input) and print out the result . Fix these problems update your post accordingly.