CodeGym/Help with Java Tasks/Help! Why don't work?

Level 11

Sumy

09.03.2019
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Help! Why don't work?

Question about the task

Multiplication table

Java Syntax, Level 4, Lesson 10

Resolved

I don't understand why this code don't work

Use a while loop to display a 10x10 multiplication table.
Separate the numbers using a space.

Example output:
1 2 3 4 5 6 7 8 9 10 2 4 6 8 10 12 14 16 18 20 3 6 9 12 15 18 21 24 27 30 4 8 12 16 20 24 28 32 36 40 5 10 15 20 25 30 35 40 45 50 6 12 18 24 30 36 42 48 54 60 7 14 21 28 35 42 49 56 63 70 8 16 24 32 40 48 56 64 72 80 9 18 27 36 45 54 63 72 81 90 10 20 30 40 50 60 70 80 90 100

Requirements:

The program should not read text from the keyboard.
The program should display text on the screen.
The program should display a 10x10 multiplication table.
The program must use a while loop.

package com.codegym.task.task04.task0434; /* Multiplication table */ import java.io.*; public class Solution { public static void main(String[] args) throws Exception { int j = 1; int i = 1; while(j<11){ while(i<11){ System.out.print(i*j); i++; } j++; System.out.println(); } //write your code here } }

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nikk_shukla

Level 10 , Mumbai, India

15 May 2019, 08:28

public class Solution { public static void main(String[] args) throws Exception { int i=1; int j=1; while (i<=10){ while(j<=10){ System.out.print(i*j+" "); j++; } System.out.println(" "); j=1; i++; } }}

hidden #10444738

Level 16

10 May 2019, 08:10

Thanks for the headsup. I was trying to use only a single loop,. Of course nested loops.

Nastya Varennikova

Level 11 , Sumy, Ukraine

11 March 2019, 13:12

Thank you very much! :)

Fernando P Spitaliere

Level 6 , Atlanta, United States

11 March 2019, 05:39

Hi, Nastya! I think there is a problem with the initialization of the variable i . In your case, that variable is NOT initialized back to 1 after it finished its while loop. It retains the value of 11, that acquired with the counter. Now, if its value is 11 (and, therefore, NOT <11) , it will not enter the while loop again. Try moving the initialization ( int i = 1) INSIDE the j while loop. Move it to line 16, in between both while loops. Oh, and remember to also include a space (" ") in your print, in between each number, like the example output shows.

Khurram

Level 16 , Lahore, Pakistan

10 March 2019, 07:30

you need to give space after every number in line 17 also when the inner while loop finishes looping the first time, at this point i = 11, so when the outer loop runs the next time, it will not loop through the inner loop because the condition i < 11 will be false every time. you need to update the value of i after the inner loop so that the inner loop runs each time. i hope my explanation makes sense

Kisszol

Level 15 , Toeroekbalint, Hungary

10 March 2019, 05:46

useful

Esperanto: ********************************************************************************** Saluton Nastya, vi havas tri problemojn: 1, Metu la linion "int i = 1;" en la internan ciklon. 2, La interna ciklo "while(i<11){" devantus sxangxi al "while(i<10){" 3, La linio "System.out.print(i*j);" devantus sxangxi al "System.out.print(i*j + " "); gxis Zoltan ************************************************************************************* English: Dear Nastya, you have three problems: 1, Remove the line "int i = 1;" into the inner circle 2, The inner circle "while(i<11){" should be changed tol "while(i<10){" 3, The line "System.out.print(i*j);" shpould be changed to "System.out.print(i*j + " "); Zoltan ps. One language above all: Esperanto

Ayush Mathur

Level 11 , Bhopal, India

10 March 2019, 13:22

I don't think that there is a need to change the condition from "while (i < 11)" to "while (i < 10)".

Kisszol

Level 15 , Toeroekbalint, Hungary

10 March 2019, 15:34

Esperanto: La interna ciklo devantus sxangxi, provu. English: The internal circle should be changed, try it out.

Ayush Mathur

Level 11 , Bhopal, India

10 March 2019, 15:56

package com.codegym.task.task04.task0434; /* Multiplication table */ import java.io.*; public class Solution { public static void main(String[] args) throws Exception { int j = 1; while(j<11){ int i = 1; while(i<10){ System.out.print(i*j + " "); i++; } j++; System.out.println(); } //write your code here } } if this is what you are saying then the output is :

Kisszol

Level 15 , Toeroekbalint, Hungary

10 March 2019, 16:24

useful

Jen mia solvo: public class Solution { public static void main(String[] args) throws Exception { int j = 1; while(j<11){ int i = 1; while(i<10){ System.out.print(i*j + " "); i++; } System.out.println(i*j); j++; } } }

Sung Ju No

Level 7 , Sao Paulo, Brazil

30 April 2019, 06:23

Hi Kisszol i would like to ask, the inner while condition is true until i = 9 so how the condition is printing the last 10 digit if the next outter condition goes direct to next line? im lost about the flow of the information

Kisszol

Level 15 , Toeroekbalint, Hungary

1 May 2019, 08:01

Globalo esperanto: Saluton Sung, kial gxi funkcias. while(i<10){ System.out.print(i*j + " "); i++; } La kialo estas simpla. La programo aldonas 1, post la kontrolo de la while loop, ne gravas la rezulto de la while loop-o. Vi povas vidi gxin en la debugger. Gxis Zoltan local english: why does it work: while(i<10){ System.out.print(i*j + " "); i++; } The reason is simple. The program adds 1, after the while loop is controlled, no matter whether it is true or not. You can see it in the debugger. Bye Zoltan ps. One language above all: Esperanto