Fail 4th requirement

Question about the task

Resolved

Tried to rework this code many times (even changed exception type in try-catch block) without any success. Please help me find the bug. Any help would be greatly appreciated.

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.util.ArrayList; import java.util.HashMap; /* Request parser */ public class Solution { public static void main(String[] args) throws Exception{ BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String input = reader.readLine(); String[] trash = input.split("\\?"); String[] split1 = trash[1].split("&"); ArrayList<String> list = new ArrayList<>(); ArrayList<String> listObject = new ArrayList<>(); for (int i = 0; i < split1.length; i++){ if(split1[i].contains("=")){ String[] split2 = split1[i].split("="); if (split2[0].equals("obj")){ list.add(split2[0]); listObject.add(split2[1]); } else { list.add(split2[0]); } } else { list.add(split1[i]); } } for (int i = 0; i < list.size(); i++){ if (i != list.size()-1){ System.out.print(list.get(i) + " "); } else { System.out.print(list.get(i) + "\n"); } } for (String s : listObject){ if (s.contains(".")){ try { double i = Double.parseDouble(s); alert(i); } catch (Exception e){ alert(s); } } else { alert(s); } } } 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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MICHAEL DUNLAP

Level 20 , Bellevue, United States

4 September 2019, 17:09

Another thing to consider for efficiency is that you DO NOT need iterate the whole list of parameter values to try parsing to a double. According to the requirements, the obj parameter of the URL is the only parameter that needs to be tested to a double value. So after printing all the parameters keys (separated by a space), I simply:

String objVal = params.get("obj");

and then if it is not null, use the try catch Robert suggested (without the break because you're not breaking a loop...only one element...and without line 9).

Robert

Level 27 , Lombard, United States

11 July 2019, 23:12

solution

Line 48 is your problem. You are only trying to parse a number if it has a period. If your number does not, (instead of 3.14 you only input 314) you are returning alert(s). Try changing lines 47-58 to read:

for (String s : listObject){
        try {
            double i = Double.parseDouble(s);
            alert(i);
            break;
        } catch (Exception e){
            alert(s);
        }
        alert(s);
}

Kotlet

Level 28 , Wroclaw, Poland

12 July 2019, 11:51

Thank you very much Robert! Finally after 13 :) attempts I have met all conditions (didn't know that they also want to parse to double integers like 314). I needed only to delete your line 9.