not able to understand help!!

Question about the task

Under discussion

I am stuck that why it is not picking up the value what's wrong in my code

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.

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

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Kotlet

Level 28 , Wroclaw, Poland

8 August 2019, 13:43

Well there are couple of things. Your if statement in line 20 is wrong. Look how syntax in hint looks like:

if (check whether the number is -1)

while you are checking if the number is less than 0 (so every negative number). Only -1 should stop the program while -2, -100 etc. should be added to variable "z". Secondly you increase your count counter before checking if passed number is -1. Therefore when you pass 1 and -1 your counter is 2 while it should be 1. Try moving your count++ to correct place. Lastly your 31 line is printing integer result (so instead of 2.8 it shows 2). The task is to display double (2.8). Look for anwser how to convert int to double. If you still have any problems let me know.

hidden #10468516

Level 5

9 August 2019, 05:47

thanks alot brother i get it but one more problem compiler shows some problem in line 11. So please help if you can

Kotlet

Level 28 , Wroclaw, Poland

9 August 2019, 09:44

Could you please share your whole code after changes? And please do it with "code" button. Also paste message from compiler.

hidden #10468516

Level 5

10 August 2019, 09:57

package com.codegym.task.task05.task0507;

/*
Arithmetic mean

*/

public class Solution {
    public static void main(String[] args) throws Exception {
        //write your code here
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int count=0;
        int z =0.0 ;

        while (true)
        {
            String s = reader.readLine();
            int a = Integer.parseInt(s);

            if (a==-1)
            {
                break;
            }
            else
            {
            z=z+a;
            }

             count++;
        }
        Double d= new Double(z);
        System.out.println(d/count);
    }
}

hidden #10468516

Level 5

10 August 2019, 09:58

Compiler output --- com/codegym/task/task05/task0507/Solution.java:11: error: cannot find symbol BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); ^ symbol: class BufferedReader location: class com.codegym.task.task05.task0507.Solution

Kotlet

Level 28 , Wroclaw, Poland

11 August 2019, 07:11

In line 2 (before comment) paste: import java.io.BufferedReader; import java.io.InputStreamReader; If you are working on inttelliJ your buffered reader and inputstreamreader in line 11 should be marked red. In such cases click on them with left mouse button, then hit alt+enter and then select import class. This error occured because some packages are not imported by default. You need to excplicitly import (or write them before every method) them in order to work with them. Also you cant write something like this:

int z =0.0 ;

0.0 is double while int z is integer. You can do something like this:

double z = 0.0;

then you can delete line 31 and change line 32 to:

System.out.println(z/count);

Because int/double = double. I hope now your program will work correctly. If not let me know :)

hidden #10468516

Level 5

11 August 2019, 07:52

Thanks alot now it works with import java.io.*;