CODEWITHSUNDEEP
javafor-loop
Seth Myers
Seth Myers

Reputation: 53

How can I reset a variable in a loop in Java?

I am writing a number-guessing game for my Computer Science 1100 class, one part of which is to print the number of attempts the player takes at guessing the target number. I've defined a variable tries to track that; the program increments it by one every time the player makes a guess.

The game restarts after the player guesses the number correctly, and at that point I want to reset the tries counter. I can't figure out how to do that, however, because the program increments tries each time the number is guessed. How can I do it?

import java.util.Scanner;
import java.util.Random;
public class Q2 {
   public static void main(String[] args) {
      Scanner kbd = new Scanner(System.in);
      Random r = new Random();
      System.out.println("Welcome to the Number Guessing Game");
      int x=0;//defining x for later
      int tries = 1;//defining tries for later
      while (x!=-1) { 
         int y = r.nextInt(101);//defining random number 0-100
         System.out.print("Guess a number between 0 and 100 or enter -1 to quit: ");
         x=kbd.nextInt();//redefining x
         x=kbd.nextInt();//redefining x
         for (int i=1;x!=-1&&x!=y;i=1) {//for loop
               if (x<-1||x>100) {//illegal condition
                  System.out.print("Out of bounds. Try again: ");
               }
               else if (x>y) {//input greater than random condition
                  System.out.print("The number is lower. Try again: ");
               }
               else if (y>x) {//random greater than input condition
                  System.out.print("The number is higher. Try again: ");
               }
               x = kbd.nextInt();//redefining x
               tries+=i;//defining pattern for tries
         }
         if (x==y) {//input=random condition
            System.out.println("Congratulations! You guessed the number in " + tries + " tries");
         }
      }
      if (x==-1) {//quit condition
         System.out.print("Thank you for playing the game!!");
         }
     }
}

Upvotes: 1

Views: 17875

Answers (2)

kdek
kdek

Reputation: 1

One possible solution would be to encapsulate your guessing game into it's own method, which will re-initialize all variables when called, and create an if condition inside of your loop if the guess is correct.

private static void guessingGame() {
    Scanner scanner = new Scanner(System.in);
    double randomNum = Math.random();
    double tries = 0, guess = 0;

    do while (!(guess == randomNum) {
        System.in("What is your guess? ");
        guess = scanner.nextDouble();
        tries++;

        if (guess == randomNum) {
           System.out.println("Guessed correctly in " + tries + " tries.");
           tries = 0;
        }
    }
}

public static void main() {
   guessingGame();
}

Upvotes: 0

Frithjof
Frithjof

Reputation: 2264

a) Change the scope of your variable

Variables are only available in the scope they are defined in. For example

while (something) { // all code inside the loop is in an inner scope
  int variable = 42;
  // variable is accessible here
}
// variable is not accessible here

This means, every time the while-loop performs one iteration, variable is newly created. It is a good practice to only define variables in the scope they actually have a meaning (in this case in the while-loop).

b) Assign the variable every time anew

Another way would be to reset the variable each time it is necessary. This would result in such a design:

int variable; // variable is defined outside the inner scope
while (something) {
  variable = 42;
  // some code that changes variable's value
}

Upvotes: 8

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