Cannot find symbol variable

Question

The error is "cannot find symbol variable b" I'd like to understand as well how to correctly write the syntax of the do while loop Thanks.

import java.util.*;

public class pract3ex10 {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        do {
            System.out.println("Enter a positive");
            int n = s.nextInt();
            int x = n;
            int m = 0;
            if (x < 0) {
                System.out.println("Thank You!");
            } else {
                while (x > 0) {
                    x = x / 10;
                    m++;
                }
                System.out.println("Number of digits in " + n + "= " + m);
            }
        } while (n > 0);

    }

}

You will need this [The while and do-while Statements](http://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html) — Smit, Apr 15 '13 at 18:13
When I compile your code in Java7 I get `n cannot be resolved to a variable` and it seems correct since `n` is defined inside `do{..}while` loop so it is out of scope for `while` condition. Maybe try to declare `int n=-1` before loop. — Pshemo, Apr 15 '13 at 18:15
A specific case of the general question http://stackoverflow.com/questions/25706216/what-does-a-cannot-find-symbol-compilation-error-mean — Raedwald, Feb 26 '16 at 20:10

score 2 · Accepted Answer · answered Apr 15 '13 at 18:13

The scope of the n variable is currently only inside the do-while block, within the braces. If you would like it to be accessible in a bigger scope, even if that means the condition for the loop, then declare it outside the loop.

int n;
do
{
    n = s.nextInt();
    ...

score 1 · Answer 2 · answered Apr 15 '13 at 18:13

1

int n;
do {
    ...
    n = s.nextInt();
    ...
} while (n > 0);

answered Apr 15 '13 at 18:13

sp00m

47,968
31
142
252

score 1 · Answer 3 · answered Apr 15 '13 at 18:48

1

n should be declared before of the do..while block...

answered Apr 15 '13 at 18:48

elopez

109
9

Cannot find symbol variable

3 Answers3