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  1. #1
    aedara is offline Member
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    Default Program not throwing exception

    I have written the below Fibonacci series program that accepts an integer to display that many numbers in the series. Works fine, but when you enter a negative number, it is supposed to throw the exception and instead it prints out the first number. It does throw an exception if I enter a character. Can you please help? Also, can you suggest if I am writing the program in an efficient way?

    import java.util.Scanner;
    public class Fibonacci {

    public static void main(String[] args) {
    int n, a, b, c, i;

    try{
    System.out.println("Please enter the number of fibonacci series you would like to print");
    Scanner input = new Scanner(System.in);
    n = input.nextInt();
    while (n == 0) {
    System.out.println("please enter a number greater than zero");
    n = input.nextInt();
    }
    a = 1;
    b = 1;
    System.out.println(a);
    for(i = 2; i<=n; i++){
    System.out.println(b);
    c = a + b;
    a = b;
    b = c;
    }

    } catch(Exception E){
    System.err.println("You did not enter a valid integer number");
    }


    }

    }

  2. #2
    JosAH's Avatar
    JosAH is offline Moderator
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    Default

    Quote Originally Posted by aedara View Post
    while (n == 0) {
    Suppose n < 0 (as you told us).

    kind regards,

    Jos
    cenosillicaphobia: the fear for an empty beer glass

  3. #3
    aedara is offline Member
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    Default

    That is true..if n < 0, it should throw an exception, but it is not. Do you know why?

  4. #4
    Junky's Avatar
    Junky is offline Grand Poobah
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    Do you want the JVM to read your mind? How is it supposed to know that if n < 0 to throw an exception if you do not tell it to do so?

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