infinite loop when trying to restart after try catch

Question

[SOLVED] By adding console.next(); to my catch statement.

catch(InputMismatchException fe) {
    System.out.println("You didnt enter an integer. Try again");
    restart = 'y';
    console.next();
}}

while(restart=='y');
}}

[Solution]^^^^^^

static public char restart;

public static void main(String[] args) {
    do {
        try {
            int num1, num2, check, sum = 0, count = 1, sqsum = 0;
            do {
                System.out.println("Please enter a number");
                num1 = console.nextInt();

Here is where i have set restart as public so i can use it with the try catch in order to restart the program when a inputmissmatchexception happens

catch(InputMismatchException fe) {
    System.out.println("You didnt enter an integer. Try again");
    restart = 'y';
}}

while(restart=='y');
}}

and here is the catch where if it does catch the exception i set restart to y then if it is y then the do while would restart the program. But it doesn't it just asks the user to enter a number then displays my catch message "you didn't enter an integer....." I believe this means the scanner isn't searching for another value to place in the variable, but i have tried and don't know how to fix this.

FULL: This is a project for school where i have to have them enter two number and do things to them. It works and does everything its supposed to but i just would like to have the program restart if the user inputs a non integer.

package p321ex9;

import java.util.*;

public class p321ex9 {
    static Scanner console = new Scanner(System.in);
    static public char restart = 'n';

    public static void main(String[] args) {
        do {
            try {
                int num1, num2, check, sum = 0, count = 1, sqsum = 0;
                do {
                    System.out.println("Please enter a number");

                    num1 = console.nextInt();

                    System.out.println("Please enter a second number that is grester than the first number you entered which "
                            + "was " + num1 + ".");

                    num2 = console.nextInt();
                    if (num1 > num2) {
                        System.out.println("the first number was greater than your second number, please enter new numbers and "
                                + "make sure the second is greater.");
                    }
                }
                while (num1 > num2);
                System.out.println("List of odd numbers between the first and second numbers you entered inclusive:");
                while (num1 <= num2) {
                    check = (num1 % 2);
                    if (check == 1) {
                        sqsum += (num1 * num1);
                        System.out.print(num1 + " ");
                    } else {
                        sum += num1;
                    }
                    num1++;
                }
                System.out.println();
                System.out.println("The sum of all even numbers the first and second numbers you entered inclusive"
                        + ": " + sum);
                System.out.println("Sum of the squares of all the odd numbers between your two entered numbers inclusive: " + sqsum);
                System.out.println("All numbers from 1 to 10 squared");
                while (count <= 10) {
                    System.out.print(count + " squared = " + (count * count) + "   ");
                    count++;
                }
            } catch (InputMismatchException fe) {
                System.out.println("You didnt enter an integer. Try again");
                restart = 'y';
            }
        }
        while (restart == 'y');

    }
}

Baby · Answer 1 · 2014-05-07T05:49:42.830

1

because when you set restart='y', you did not reset it when user enter valid input (integer)

Better way of doing this:

public static void main (String[] args){

    Scanner console=new Scanner(System.in);
    int num1,num2,check,sum=0,count=1,sqsum=0;
    do{
        System.out.println("Please enter a number");
        String input=console.nextLine();

        if(input.replaceAll("\\d","").length()==0){
            num=Integer.parseInt(input);
            restart='n';
        }
        else{
            System.out.println("You didnt enter an integer. Try again");
            restart='y';
        }
    }
    while (restart=='y');
}

edited May 07 '14 at 05:49

answered May 07 '14 at 05:42

Baby

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i tried changing it to 'n' before the "please enter a number" question but still get the infinite loop. I dont think i understood what u meant could u explain a little more please? – user3600390 May 07 '14 at 05:51
which part you don't understand? – Baby May 07 '14 at 05:54
i wrote that right before u edited – user3600390 May 07 '14 at 06:02
so I guess problem was solved – Baby May 07 '14 at 06:06
actually no it didnt work like i thought it would ill post full code so u can see what im trying to do . If you dont have time to help its k. – user3600390 May 07 '14 at 06:09

infinite loop when trying to restart after try catch

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