public static void main(String[] args) {
Scanner Keyboard = new Scanner(System.in);
System.out.println("Enter your name: ");
String firstname =Keyboard.nextLine();
System.out.println("Welcome "+ firstname+ "!"+ " Please answer the following questions:");
int x = (int)(20 * Math.random()) + 1;
int y = (int)(20 * Math.random()) + 1;
int sum = (x+y);
System.out.println(x + " + " + y + " = ");
String sInput = Keyboard.nextLine();
int answer1 = Integer.parseInt(sInput);
if (answer1 ==sum){
System.out.println("Correct!");
}else{
System.out.println("Wrong!");
}
System.out.println("The correct answer is " +sum);
I have no clue on how to keep track of the correct answers. I need something to keep track of when it prints correct. I don't know what to do though. I know I just need to record the corrects and divide by four. Four because thats how many questions I have in my quiz.
If you just need to keep track of how many right answers were provided, just add an int variable starting with 0 as a value and increment it. If you want to keep track of the questions and answers which were right, create an empty ArrayList and add a string every time a correct answer is provided.
Here an example of the second option:
ArrayList<String> correctAnswers = new ArrayList<String>();
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter your name: ");
String firstname =keyboard.nextLine();
System.out.println("Welcome "+ firstname+ "!"+ " Please answer the following questions:");
for (int i=0;i<10;i++) {
int x = (int)(20 * Math.random()) + 1;
int y = (int)(20 * Math.random()) + 1;
int sum = (x+y);
System.out.println(x + " + " + y + " = ");
String sInput = keyboard.nextLine();
int answer1 = Integer.parseInt(sInput);
if (answer1 ==sum){
System.out.println("Correct!");
correctAnswers.add(x + " + " + y + " = " + sum);
}
else{
System.out.println("Wrong!");
System.out.println("The correct answer is " +sum);
}
}
System.out.println("Correct answers:");
for (String correctAnswer : correctAnswers) {
System.out.println(correctAnswer);
}
It asks 10 questions, keeps track of the right answers and outputs them after the 10th question.
An example for the first option:
int correctAnswers=0;
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter your name: ");
String firstname =keyboard.nextLine();
System.out.println("Welcome "+ firstname+ "!"+ " Please answer the following questions:");
int totalAnswers=4;
for (int i=0;i<totalAnswers;i++) {
int x = (int)(20 * Math.random()) + 1;
int y = (int)(20 * Math.random()) + 1;
int sum = (x+y);
System.out.println(x + " + " + y + " = ");
String sInput = keyboard.nextLine();
int answer1 = Integer.parseInt(sInput);
if (answer1 ==sum){
System.out.println("Correct!");
correctAnswers++;
}
else{
System.out.println("Wrong!");
System.out.println("The correct answer is " +sum);
}
}
System.out.println("Correct answers: "+ correctAnswers + "("+correctAnswers*100/totalAnswers+"%)");
Related
I need to first ask the user to input how many problems they want to do. Then generate the first, then the second after they answer the first and so on.
public static void main(String[] args) {
int number1 = (int) (Math.random() * 40 + 10), number2 = (int) (Math.random() * 40 + 10), uanswer, ianswer, counter, icounter,
acounter, counter1, ui, aacounter, bcounter;
Scanner input = new Scanner(System.in);
System.out.println("How many problems do you want to do?");
ui = input.nextInt();
counter = 1;
icounter = 1;
acounter = counter + icounter;
{
System.out.print("What is " + number1 + " + " + number2 + "? ");
}
uanswer = input.nextInt();
ianswer = number1 + number2;
while (counter < 10000 && icounter < 1000 && acounter < 1000 && number1
+ number2 != uanswer) {
System.out.println("Incorrect, the answer is "
+ ianswer + ", " + icounter + " out of " + icounter + " incorrect. Try again?");
icounter++;
acounter++;
uanswer = input.nextInt();
}
if (ianswer == ianswer) {
aacounter = acounter - 1;
bcounter = icounter - 1;
System.out.println("Correct, the answer is " + ianswer
+ ", " + counter + " out of " + aacounter + " correct, "
+ bcounter + " out of " + aacounter + " incorrect.");
}
}
With my current code, I only see one problem, even though I asked for 2 or more problems at the beginning.
You need to add a loop around this statement:
System.out.print("What is " + number1 + " + " + number2 + "? ");
like:
for(int i=0; i<ui; i++){
System.out.print("What is " + number1 + " + " + number2 + "? ");
...
This question already has answers here:
What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?
(26 answers)
IndexOutOfBounds with array
(5 answers)
Closed 6 years ago.
The basic idea of this assignment is to create a program that can provide a summary and identify who won a "match" in a sports event (football, basketball, Soccer, baseball, etc.)
**This is my code:**
`import java.util.Scanner;
public class Team {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
// Ask questions about the game type etc.
System.out.println("Please enter game name: ");
String gameName = sc.next();
System.out.println("Please enter " + gameName + " team 1 name: ");
String t1N = sc.next();
System.out.println("Please enter " + gameName + " team 2 name: ");
String t2N = sc.next();
System.out.println("What is a score in " + gameName + " called? ");
String scoreName = sc.next();
System.out.println("How many points per " + scoreName + " in " + gameName + "?");
int scoreValue = sc.nextInt();
System.out.println("What is a period in " + gameName + " called?");
String periodName = sc.next();
System.out.println("How many " + periodName + " in " + gameName + "?");
int numberOfPeriods = sc.nextInt();
int sum1 = 0;
int sum2 = 0;
for (int i = 1; i <= numberOfPeriods; i++) {
System.out.println(periodName + " #" + i);
System.out.println("How many " + scoreName + " for " + t1N + "?");
int numberOfScoresT1[] = new int[sc.nextInt()];
System.out.println("How many " + scoreName + " for " + t2N + "?");
int numberOfScoresT2[] = new int[sc.nextInt()];
for (int counter = 0; counter < numberOfScoresT1.length; counter++)
sum1 += numberOfScoresT1[counter];
for (int counter = 0; counter < numberOfScoresT1.length; counter++)
sum2 += numberOfScoresT2[counter];
}
System.out.println("Team 1 scored " + sum1 + " team 2 scored " + sum2);
}`
This is the error I'm receiving:
Please enter game name:
Football
Please enter Football team 1 name:
Dolphins
Please enter Football team 2 name:
Jaguars
What is a score in Fotball called?
Touchdown
How many points per Touchdown in Fotball?
7
What is a period in Fotball called?
Quarter
How many Quarter in Fotball?
4
Quarter #1
How many Touchdown for Dolphins?
3
How many Touchdown for Jaguars?
2
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 2
at Team.main(Team.java:36)
I recognize that the arrays I'm using are in the for loop, and I think thats what is causing the problem, but i'm not sure how to fix it.
This is a sample output is supposed to look like:
Quarter #1:
How many Touchdowns for Dolphins? 2
How many Touchdowns for Chargers? 1
Quarter #2:
How many Touchdowns for Dolphins? 0
How many Touchdowns for Chargers? 1
Quarter #3:
How many Touchdowns for Dolphins? 0
How many Touchdowns for Chargers? 2
Quarter #4:
How many Touchdowns for Dolphins? 3
How many Touchdowns for Chargers? 0
Football Game Results:
Dolphins scored 5 Touchdowns for a score of 35
Chargers scored 4 Touchdowns for a score of 28
Dolphins Win by 7 points!
for (int counter = 0; counter < numberOfScoresT1.length; counter++)
sum2 += numberOfScoresT2[counter];
Should the second parameter of the loop be
for (int counter = 0; counter < numberOfScoresT2.length; counter++)
seeing as you are accessing numberOfScoresT2 array in the body.
Your inner for loops should be as follows
for (int counter = 0; counter < numberOfScoresT1.length; counter++)
sum1 += numberOfScoresT1[counter];
for (int counter = 0; counter < numberOfScoresT2.length; counter++)
sum2 += numberOfScoresT2[counter];
You have used length of array numberOfScoresT1 instead of array numberOfScoresT2 in second inner for loops.
import java.util.Scanner;
public class Team {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
// Ask questions about the game type etc.
System.out.println("Please enter game name: ");
String gameName = sc.next();
System.out.println("Please enter " + gameName + " team 1 name: ");
String t1N = sc.next();
System.out.println("Please enter " + gameName + " team 2 name: ");
String t2N = sc.next();
System.out.println("What is a score in " + gameName + " called? ");
String scoreName = sc.next();
System.out.println("How many points per " + scoreName + " in " + gameName + "?");
int scoreValue = sc.nextInt();
System.out.println("What is a period in " + gameName + " called?");
String periodName = sc.next();
System.out.println("How many " + periodName + " in " + gameName + "?");
int numberOfPeriods = sc.nextInt();
int sum1 = 0;
int sum2 = 0;
int numberOfScoresT1[] = new int[numberOfPeriods];
int numberOfScoresT2[] = new int[numberOfPeriods];
for (int i = 0; i <numberOfPeriods; i++) {
System.out.println(periodName + " #" + i);
System.out.println("How many " + scoreName + " for " + t1N + "?");
numberOfScoresT1[i] = sc.nextInt();
System.out.println("How many " + scoreName + " for " + t2N + "?");
numberOfScoresT2[i] = sc.nextInt();
}
sc.close();
for (int counter = 0; counter < numberOfPeriods; counter++) {
sum1 += numberOfScoresT1[counter];
sum2 += numberOfScoresT2[counter];
}
System.out.println("Team 1 scored " + sum1 + " team 2 scored " + sum2);
}
}
import java.util.Random;
import java.util.Scanner;
public class LotteryGame{
public static void main(String[] args) {
int NUM_DIGITS = 6;
int[] userDigits = new int[NUM_DIGITS];
int[] lotteryNumbers = new int[NUM_DIGITS];
int sameNum;
generateNumbers(lotteryNumbers);
getUserData(userDigits);
sameNum = compareArrays(lotteryNumbers, userDigits);
System.out.println("Winning numbers: " + lotteryNumbers[0] + " "
+ lotteryNumbers[1] + " " + lotteryNumbers[2] + " "
+ lotteryNumbers[3] + " " + lotteryNumbers[4] + " " + lotteryNumbers[5] + " ");
System.out.println("Your numbers: " + userDigits[0] + " "
+ userDigits[1] + " " + userDigits[2] + " " + userDigits[3]
+ " " + userDigits[4] + " " + userDigits[5] +" ");
System.out.println("Number of matching digits: " + sameNum);
if (sameNum == 6) {
System.out.println("First prize!!!");
}
if (sameNum == 5) {
System.out.println("Second prize!!!");
}
if (sameNum == 0) {
System.out.println("No matching numbers, you lost.");
}
}
public static void generateNumbers(int[] lotteryNumbers) {
Random randNum = new Random();
lotteryNumbers[0] = randNum.nextInt(59);
lotteryNumbers[1] = randNum.nextInt(59);
lotteryNumbers[2] = randNum.nextInt(59);
lotteryNumbers[3] = randNum.nextInt(59);
lotteryNumbers[4] = randNum.nextInt(59);
lotteryNumbers[5] = randNum.nextInt(59);
return lotteryNumbers[5];
}
public static void getUserData(int[] userDigits) {
Scanner keyboard = new Scanner(System.in);
System.out.print("Enter first digit: ");
userDigits[0] = keyboard.nextInt();
System.out.print("Enter second digit: ");
userDigits[1] = keyboard.nextInt();
System.out.print("Enter third digit: ");
userDigits[2] = keyboard.nextInt();
System.out.print("Enter fourth digit: ");
userDigits[3] = keyboard.nextInt();
System.out.print("Enter fifth digit: ");
userDigits[4] = keyboard.nextInt();
System.out.print("Enter sixth digit: ");
userDigits[5] = keyboard.nextInt();
return userDigits[5];
}
public static int compareArrays(int[] userDigits, int[] lotteryNumbers) {
int sameNum = 0;
for (int i = 0; i < 6; i++) {
for (int x = 0; x < 5; x++) {
if (lotteryNumbers[i] == userDigits[x]) {
sameNum++;
}
}
}
return sameNum;
}
}
When I compile I get the following errors-
LotteryGame.java:51: error: incompatible types: unexpected return value
return lotteryNumbers[5];
^
LotteryGame.java:72: error: incompatible types: unexpected return value
return userDigits[5];
^
2 errors
Can any of you help me with these compilation errors? I'm trying to get this to work. The user is supposed to input 6 numbers, and the program is supposed to pick randomly 6 numbers. Using these numbers, the program will compare the numbers with echoed input.
generateNumbers and getUserData are void functions, meaning they don't return anything, so you can't return anything from them.
You probably want to declare them as functions returning int instead:
public static int generateNumbers(int[] lotteryNumbers)
Univerio is correct in answering your original question.
Looking at your test code you might consider removing the return statement on those two functions since you are just populating both arrays.
Apologies for the silly question, I am currently struggling to learn java. I need this code to work so that it will repeat unless '0' is entered for the studentNumber, I'm unsure of how to get the "please enter student number" part to work when I have to declare the int for that before the if statement? I'm not sure if I've approached this completely wrong or what, but I need to be able to repeat the data entry unless "0" is entered as the studentNumber. Thanks for any help!
class Main {
public static void main( String args[] ) {
int studentNumber = BIO.getInt();
if(studentNumber > 0) {
System.out.print("#Please enter the student number : ");
System.out.print("#Please enter the coursework mark : ");
int courseWork = BIO.getInt();
System.out.print("#Please enter the exam mark : ");
int examMark = BIO.getInt();
double average = (double)(courseWork + examMark) / 2;
System.out.printf("sn = " + studentNumber
+ " ex = " + examMark + " cw = " + courseWork
+ " mark = " + average);
} else {
System.out.print("#End of data");
}
}
}
}
Use while()
while(studentNumber > 0){
studentNumber = BIO.getInt();
.........
........
}
See also
while in Java
Use while() instead of if, along with the following changes:
System.out.print("#Please enter the student number : ");
int studentNumber = BIO.getInt();
while(studentNumber > 0) {
System.out.print("#Please enter the coursework mark : ");
int courseWork = BIO.getInt();
System.out.print("#Please enter the exam mark : ");
int examMark = BIO.getInt();
double average = (double)(courseWork + examMark) / 2;
System.out.printf("sn = " + studentNumber
+ " ex = " + examMark + " cw = " + courseWork
+ " mark = " + average);
System.out.print("#Please enter the student number : ");
studentNumber = BIO.getInt();
}
System.out.print("#End of data");
This, as opposed to the other answers, will ensure that even in the first iteration, you perform the check (and promt the user for the student number).
Using Scanner to get the input from the user and process the input value
import java.util.Scanner;
public class ConditionCheck {
public static void main(String[] args) {
Scanner BIO = new Scanner(System.in);
System.out.print("#Please enter the student number : ");
int studentNumber = BIO.nextInt();
if(studentNumber > 0) {
System.out.print("#Please enter the coursework mark : ");
int courseWork = BIO.nextInt();
System.out.print("#Please enter the exam mark : ");
int examMark = BIO.nextInt();
double average = (double)(courseWork + examMark) / 2;
System.out.printf("sn = " + studentNumber
+ " ex = " + examMark + " cw = " + courseWork
+ " mark = " + average);
} else {
System.out.print("#End of data");
}
}
}
You should be using a while statement and do something as below:
class Main
{
public static void main( String args[] )
{
int studentNumber = 1;
While(studentNumber > 0)
{
studentNumber = BIO.getInt();
System.out.print("#Please enter the student number : ");
System.out.print("#Please enter the coursework mark : ");
int courseWork = BIO.getInt();
System.out.print("#Please enter the exam mark : ");
int examMark = BIO.getInt();
double average = (double)(courseWork + examMark) / 2;
System.out.printf("sn = " + studentNumber + " ex = " + examMark + " cw = " + courseWork + " mark = " + average);
}
else
{
System.out.print("#End of data");
}
}
}
My program is not allowing me to enter user input if i do not enter a number and i want to go through the program again, it think its due to a hanging token somewhere but i cannot seem to find it.
import java.util.Scanner;
public class LessonTwo {
static Scanner userInput = new Scanner(System.in);
public static void main(String[] args) {
char answer = ' ';
do {
System.out.print("Your favorite number: ");
if (userInput.hasNextInt()) {
int numberEntered = userInput.nextInt();
userInput.nextLine();
System.out.println("You entered " + numberEntered);
int numEnteredTimes2 = numberEntered + numberEntered;
System.out.println(numberEntered + " + " + numberEntered
+ " = " + numEnteredTimes2);
int numEnteredMinus2 = numberEntered - 2;
System.out.println(numberEntered + " - 2 " + " = "
+ numEnteredMinus2);
int numEnteredTimesSelf = numberEntered * numberEntered;
System.out.println(numberEntered + " * " + numberEntered
+ " = " + numEnteredTimesSelf);
double numEnteredDivide2 = (double) numberEntered / 2;
System.out.println(numberEntered + " / 2 " + " = "
+ numEnteredDivide2);
int numEnteredRemainder = numberEntered % 2;
System.out.println(numberEntered + " % 2 " + " = "
+ numEnteredRemainder);
numberEntered += 2; // *= /= %= Also work
numberEntered -= 2;
numberEntered++;
numberEntered--;
int numEnteredABS = Math.abs(numberEntered); // Returns the
int whichIsBigger = Math.max(5, 7);
int whichIsSmaller = Math.min(5, 7);
double numSqrt = Math.sqrt(5.23);
int numCeiling = (int) Math.ceil(5.23);
System.out.println("Ceiling: " + numCeiling);
int numFloor = (int) Math.floor(5.23);
System.out.println("Floor: " + numFloor);
int numRound = (int) Math.round(5.23);
System.out.println("Rounded: " + numRound);
int randomNumber = (int) (Math.random() * 10);
System.out.println("A random number " + randomNumber);
} else {
System.out.println("Sorry you must enter an integer");
}
System.out.print("Would you like to try again? ");
answer = userInput.next().charAt(0);
}while(Character.toUpperCase(answer) == 'Y');
System.exit(0);
}
}
Yes you are right you need to consume the characters first after the user inputted character in the nextInt before allowing the user to input data again
just add this in your else block and it will work:
else {
System.out.println("Sorry you must enter an integer");
userInput.nextLine(); //will consume the character that was inputted in the `nextInt`
}
EDIT:
change this:
answer = userInput.next().charAt(0);
to:
answer = userInput.nextLine().charAt(0);