I get error saying infinite loop.Please help.

Question about the task

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package com.codegym.task.task05.task0507; /* Arithmetic mean */ import java.io.*; public class Solution { public static void main(String[] args) throws Exception { //write your code here BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); int a = Integer.parseInt(reader.readLine()); System.out.println(a); int count = 0; int sum = 0; double mean =0; while(true) { if(a==-1) { break; } else { count++; sum = sum + a; } } mean = (double)sum/count; System.out.println(mean); } }

Use the keyboard to enter numbers, and then calculate the arithmetic mean.
If the user enters -1, display the arithmetic mean of all entered numbers and end the program.
-1 should not be included in the calculation.

Here are some examples:
a) if you enter the numbers
1
2
2
4
5
-1
then we display
2.8

b) if you enter the numbers
4
3
2
1
-1
then we display
2.5

Hint: one of the solutions to this problem uses the following construct:

while (true) {
    int number = read the number;
    if (check whether the number is -1)
        break;
}

Requirements:

The program must read data from the keyboard.
The program should display data on the screen.
After entering -1, the program must correctly terminate.
If you sequentially enter the numbers 1, 2, 2, 4, 5 and -1, the program should display 2.8.
If you sequentially enter the numbers -100, 0, 100, and -1, the program should display 0.0.
If you sequentially enter the numbers 1 and -1, the program should display 1.0.
The displayed result should match the task conditions for any input data.

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Alexander Hernandez

Level 11 , Logan, United States

24 July 2019, 15:28

Since the variable a reads once from the keyboard, there can be two unexpected outcomes: 1. a will be used once in the loop (if a is equal to -1) though since nothing has been added to the count and sum variables, it will result in a "divide by zero" exception. 2. The loop will run infinite times (if a is equal to a value other than -1) . This is what triggers the infinite loop error: Say the user inputs 8 as the value for a: the comparison (Line 19) will return false (8 is not equal to -1) so program moves on to the else branch. Variable count will be incremented by 1, and variable sum will now be equal to 8. Then the loop will run again, doing the same instruction as stated in the previous section: count will be equal to 2, sum equal to 16 and so forth. Note that Lines 30 and 32 will never be run because the program is still circling around the loop. -------------------------------------------------------------------------------------------------------------------------- The line of code that reads the number from the user (int variable a at Line 12) should moved before the if-else statements inside the while (true) loop. When the program is run, the loop will run and read a value from the user. That value will be checked through the conditional statements and then loop back again, reading a number until the a is equal to -1.

Anusha Govindarajan

Level 7 , Amsterdam, Netherlands

24 July 2019, 16:10

Yes thank you.I completed the task and also got what was wrong.