不在if / else语句中打印我的代码

Question

So im creating jeapordy in java, and i dont care that i spelt it wrong(if i did) but i only have one question coded so far with only one answer, and it asks the question but only prints out you are wrong even if the answer is right.

it is asking the first history question and the answer is george, but it is printing out that the answer is wrong. the first history question is also worth 100. i have not began to code the math part yet.

thanks if you can help fin my problem! its probably really simple as i am a beginner.

import java.util.Random;
import java.util.Scanner;

public class game {
public static void main (String[] args){
    //Utilites
    Scanner s = new Scanner(System.in);
    Random r = new Random();

    //Variables
    String[] mathQuestions;
    mathQuestions = new String[3];
    mathQuestions[0] = ("What is the sum of 2 + 2");
    mathQuestions[1] = ("What is 100 * 0");
    mathQuestions[2] = ("What is 5 + 5");

    String[] historyQuestions;
    historyQuestions = new String[3];
    historyQuestions[0] = ("What is General Washingtons first name?");
    historyQuestions[1] = ("Who won WWII, Japan, or USA?");
    historyQuestions[2] = ("How many states are in the USA?");


    //Intro
    System.out.println("Welome to Jeapordy!");
    System.out.println("There are two categories!\nMath and History");
    System.out.println("Math       History");
    System.out.println("100          100");
    System.out.println("200          200");
    System.out.println("300          300");


    System.out.println("Which category would you like?");
        String categoryChoice = s.nextLine();
    System.out.println("For how much money?");
        int moneyChoice = s.nextInt();
            if (categoryChoice.equalsIgnoreCase("history")){
                if (moneyChoice == 100){
                    System.out.println(historyQuestions[0]);
                    String userAnswer = s.nextLine();
                    s.nextLine();
                    if (userAnswer.equalsIgnoreCase("george")){
                        System.out.println("Congratulations! You were right");
                    }
                    else{
                        System.out.println("Ah! Wrong answer!");
                    }

                }
            }

        }
}

Answer 1

When you call nextInt() , a newline character is left unread, so a subsequent call to nextLine() will return an empty string (since it reads up to the end of the line). Call newLine() once prior to read/discard this trailing newline:

if (moneyChoice == 100) {
    System.out.println(historyQuestions[0]);
    s.nextLine();  // <--
    String userAnswer = s.nextLine();
    System.out.println(userAnswer);
    ...

As an aside, don't forget to close your Scanner when you're finished with it: s.close() .

Answer 2

int moneyChoice = s.nextInt(); reads only the integer. It leaves a newline pending reading. Then String userAnswer = s.nextLine() ; reads an empty line that is obviously different from "george". Solution: read the newline immediately after the int, and do so in the whole program. You could prefer to create your own method nextIntAndLine() .

int moneyChoice= s.nextInt() ;
s.nextLine();