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Question about the task

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I've been scouring the internet for hours trying to piece this one together. My code feels sloppy, I'm exhausted, and I know it has to do something with the alert(String value) method. Can someone prod me in the right direction? I feel so freakin' stupid.

Read a URL from the console.
Display a space-delimited list of all the parameters (The parameters follow the "?" and are separated by "&", e.g. "lvl=15").
The URL contains at least 1 parameter.
The parameters must be displayed in the same order in which they are present in the URL.
If the obj parameter is present, pass its value to the relevant alert method.
alert(double value) - for numbers (fractional numbers have a decimal point)
alert(String value) - for strings
Note that the alert method must be called AFTER the list of all parameters is displayed.

Example 1

Input:
http://codegym.cc/alpha/index.html?lvl=15&view&name=Amigo

Output:
lvl view name

Example 2

Input:
http://codegym.cc/alpha/index.html?obj=3.14&name=Amigo

Output:
obj name double: 3.14

Requirements:

The program should read only one line from the keyboard.
The Solution class must not have static fields.
The program must display data on the screen in accordance with the task conditions.
The program should call the alert method with the double parameter if the obj parameter can be correctly converted to a double.
The program should call the alert method with the String parameter if the obj parameter CANNOT be correctly converted to a double.

package com.codegym.task.task15.task1527; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.URL; /* Request parser */ public class Solution { public static void main(String[] args) throws IOException { URL url = null; BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); url = new URL(reader.readLine()); String _Query = url.getQuery(); String[] arrOfStr = _Query.split("&"); for (String a : arrOfStr) { if (a.contains("=")) { int index = a.indexOf("="); a = a.substring(0, index); System.out.print (a + " "); } } System.out.println(); for (String a : arrOfStr) { if (a.contains("=")) { int index = a.indexOf("="); a = a.substring(index + 1); try { alert(Double.parseDouble(a)); } catch (NumberFormatException e) { alert(a); } } } } public static void alert(double value) { System.out.println("double: " + value); } public static void alert(String value) { System.out.println("String: " + value); } }

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Ron R

Level 2 , Washington, United States

22 January 2021, 01:30

solution

Looks pretty good, you're just missing one line and have to fix a condition. When the input is: http://codegym.cc/alpha/index.html?lvl=15&view&name=Amigo The output should be: lvl view name When I run your code, it outputs: lvl name double: 15.0 String: Amigo (You're missing "view"). Let's first address why "view" doesn't print. You're just missing an else statement in your first for-loop.

for (String a : arrOfStr) {
                if (a.contains("=")) {
                    int index = a.indexOf("=");
                    a = a.substring(0, index);
                    System.out.print (a + " ");
                } else {
                   System.out.print(a + " ");
                   }
              }

Now it should output: lvl view name double: 15.0 String: Amigo Still not there, because it shouldn't print anything after "lvl view name". But, too easy, all you have to do is correct an "if" statement. Currently, in your second for-loop you have:

if (a.contains("=")

However, it should be

if (a.contains("obj")

That should fix everything. It should also run the other input scenario. Hopefully, this helped. Regards.

Oliver Heintz

Level 18 , Mustang, United States

23 January 2021, 03:17

Thanks, that did it. I still don't understand that much about the task, but I don't know that much about URLs in general, so no surprise there. I am just reminded again how much I still don't know.

Ron R

Level 2 , Washington, United States

23 January 2021, 03:49

Trust me, I hear ya. I'm surprised how useful the, "A new question about the task that you've already completed," notification has been. Reading someone else's code, comparing and contrasting the different style, and then trying to understand what it's doing to provide help, has helped me tremendously. Your question helped me probably just as much as my help helped you. Regards.

Nouser

Level 36 , Germany

23 January 2021, 12:26

Just a hint to improve your code a little bit... instead of having an else clause just move the output out of the if block.

Guadalupe Gagnon

Level 37 , Tampa, United States

21 January 2021, 14:44

#1 It looks like this code only works when an equal = sign is present. If no equal sign is present then nothing is output. For example, if I changed the URL from the tasks example so that the args are: "....?lvl&view&name" Nothing is displayed but it should still display all three of those args. #2 The code should only call the alert method on the value of the "obj" parameter (if "obj" is present then the value following only the equals sign after "obj"). This code calls alert on anything following any equals sign.