CODEWITHSUNDEEP
java
K2SO Ghost Spirit
K2SO Ghost Spirit

Reputation: 1291

Java Loop/User Input from Scanner

Making just a simple basketball program where I ask for the home team name, how many games are in the season, and then in a loop ask for the next team game. Basically when I start the do-while loop, it works great, unless the user types in for example, "Ohio State." The out put will then go from "6 games remaining" to "4 games remaining" for example. Usually it will just ask opponent?, then decrement by one game.

How can I fix so that a 2 word basketball team name doesn't decrement twice? 

import java.util.Scanner;

public class Basketball2 {


public static void main(String[] args) throws java.io.IOException {
    Scanner scanInput  = new Scanner(System.in);
    String sHomeTeam;
    String sAwayTeam;
    int iNumGames;
    int iGamesLeft = 0;

    System.out.println("Enter home team's name: ");
    sHomeTeam = scanInput.nextLine();
    System.out.println(sHomeTeam);

    System.out.println("How many games are in the home team's basketball season?");
    iNumGames = scanInput.nextInt();
    System.out.println(iNumGames);

    //start looping
    do {
        System.out.println("Enter opponent team's name: ");
        sAwayTeam = scanInput.next();
        System.out.println(sAwayTeam);
        iGamesLeft = --iNumGames;
        System.out.println("There are " + iGamesLeft + " games left in the basketball season");


    }//end do
    while(iGamesLeft > 0);

Upvotes: 5

Views: 16648

Answers (4)

Don
Don

Reputation: 526

Replace: sAwayTeam = scanInput.next(); with sAwayTeam = scanInput.nextLine(); The reason it loops twice is because scanInput.next(); only returns one token (e.g. word) at a time. When you enter two words it doesn't need receive more input from the user before continuing a second time because it already has another word to return. Hence the double loop.

You also need to take care of the line of code that calls nextInt(). This works like the next() method, but, instead of a token (word), it scans in just one character as an int. Try this: after iNumGames = scanInput.nextInt(); put scanInput.nextLine(); This should clear scanInput of anything that is making it skip. Note: because of the way that your code is written, this will only read one character. If you need to read more than one character you should use nextLine() and assign its value to an integer.

Upvotes: 4

rafiqul786
rafiqul786

Reputation: 19

Subject: 'Java Loops' with Scanner

The simple Java program I wrote is working perfectly, you can try for yourself...and you also can convert this program easily into 'while loop', 'do - while loop' and 'for - each loop'.

Rafiq, VA, USA, Dated: 04/17/2015

//Examples: 'for loop' with Scanner
package com.java_basics;

import java.util.Scanner;

public class ForLoop_Examples_With_Scanner 
{
    public static void main(String[] args) 
    {
        //Creating instance of Scanner to allows a user's input to read from System.in
        Scanner mySC = new Scanner(System.in);
        System.out.println("Please, enter the value of 'int i' between '0 and 2' : ");
        int i = mySC.nextInt();

        System.out.println("Please, enter the value of 'exitPoint' between '10 and 1000' :");
        int exitPoint = mySC.nextInt();

        System.out.println("Please, enter the value of 'increment' between '1 and 2' :");
        int increment = mySC.nextInt();

        mySC.close();//Releasing memory to the OS (Operating System) for reuse

        System.out.println("Output:\n" + "======");
        for(;i<exitPoint ; i=i+increment)//i++==>i=i+1==>i=i+increment
        {
            System.out.println(i);          
        }
    }
}

Upvotes: 0

Rais Alam
Rais Alam

Reputation: 7016

try below code with all exit functionality also.

import java.util.Scanner;

public class Basketball2 {

    public static void main(String[] args) throws java.io.IOException {
        Scanner scanInput = new Scanner(System.in);
        String sHomeTeam;
        String sAwayTeam;
        int iNumGames;
        int iGamesLeft = 0;

        System.out.println("Enter home team's name: ");
        sHomeTeam = scanInput.nextLine();
        System.out.println(sHomeTeam);

        System.out
                .println("How many games are in the home team's basketball season?");
        iNumGames = scanInput.nextInt();
        System.out.println(iNumGames);

        // start looping
        do {
            System.out.println("Enter opponent team's name: ");
            scanInput = new Scanner(System.in);
            sAwayTeam = scanInput.nextLine();
            if(!"".equals(sAwayTeam.trim()) && !"exit".equals(sAwayTeam.trim()))
            {

                System.out.println(sAwayTeam);
                iGamesLeft = --iNumGames;
                System.out.println("There are " + iGamesLeft+ " games left in the basketball season");

            }

        }// end do
        while (iGamesLeft > 0 && !"exit".equalsIgnoreCase(sAwayTeam));
    }
}

Upvotes: 1

Rameshwar.S.Soni
Rameshwar.S.Soni

Reputation: 608

Whatever is said in the answer given by Donny Schrimsher is correct. All that you have to do now is after getting the number of games in the home team's basketball season i.e.

System.out.println("How many games are in the home team's basketball season?");
iNumGames = scanInput.nextInt();

You have to add 

scanInput.nextLine();

This is because after entering the number of games you press enter key (end of line) and nextInt() method takes the number of games and not the end-of-line. This end-of-line is consumed by the nextLine() method which Donny Schrimsher mentioned in the do-while loop. SO to avoid this you add an extra nextLine() method.

Thus it has to be 

System.out.println("How many games are in the home team's basketball season?");
iNumGames = scanInput.nextInt();
scanInput.nextLine();
System.out.println(iNumGames);

plus the changes mentioned by Donny Schrimsher.

Thanks

Upvotes: 3

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