CodeGym/Help with Java Tasks/[3rd req. X ] My outputs are corrects, but the Robot is t...

Level 19

Bordeaux

27.05.2021
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9comments

[3rd req. X ] My outputs are corrects, but the Robot is tellin' me nooOOooOOOo

Question about the task

Request parser

Java Core, Level 5, Lesson 12

Under discussion

Well, I don't understand in which case I'm wrong, even when I test with a custom link...

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.lang.reflect.Array; import java.util.*; /* Request parser */ public class Solution { public static void main(String[] args) { //write your code here String url = new Scanner(System.in).nextLine(), parameters = ""; Double valeur = null; ArrayList<Character> listChar = new ArrayList<>(); for (Character c : url.toCharArray() ) { listChar.add(c); } Iterator<Character> iterator = listChar.iterator(); while (iterator.hasNext()) { Character c = iterator.next(); if (c.equals('?')) { if (!url.contains("obj")) { while (iterator.hasNext()) { Character d = iterator.next(); //System.out.print(d); if (d.equals('&')) parameters += " "; else if (Character.isDigit(d) || d.equals('=')) ; else if (Character.isUpperCase(d)) break; else parameters += d; } } else { while (iterator.hasNext()) { Character d = iterator.next(); String doubleString = ""; while (iterator.hasNext() && valeur == null && !d.equals('&') ) { if (!(Character.isAlphabetic(d)) && !d.equals('=')) { doubleString += d; } d= iterator.next(); } if (!doubleString.isEmpty()) { valeur = Double.valueOf(doubleString); } //System.out.print(d); if (!parameters.contains("obj"))parameters+="obj"; if (d.equals('&')) parameters += " "; else if ( d.equals('=')) ; else if (Character.isUpperCase(d)) break; else parameters += d; } } } } alert(parameters); if (valeur != null) alert(valeur); } 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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Thomas

Level 41 , Bayreuth, Germany

27 May 2021, 11:38

You're trying to add to much functionality into one loop. That's why you use the !url.contains("obj") condition and this again will make everything fail cause you assume that the obj parameter always has to be at the first position. What if it is not? (I haven't looked further as that already makes your code break) If you really want to do that with an Iterator and a Character list then I'd save intermediate results in second list. Go through your String and save everyrthing betwenn ? and &s like test.com?part1&part2&part3&part5 Add these entire parts to your second list. That should be pretty easy and then go through these intermediate results and do your further checking as CG asks, like having a look if one of the parts is the obj parameter (starts with obj=) and do as required or if one of the individual parts parameter has a value. Btw. far easier would be to have a look at the String methods. There are some that do what you need out of the box (split) or you could combine some (like indexOf and substring) to get the parts out of the URL. And you output to much. When I run your code with the second example I get String: obj name double: 3.14 but the requested output is without String:

Sansho

Level 19 , Bordeaux, France

28 May 2021, 09:30

Hi Thomas, thanks for your answer and the split tip! (and nice firstname btw) I have refactored my code by following your advices, it still doesn't validate but now it's a bit less spaghetti :) For the "String: " and "double: ", it was already put by default, but even when I remove these, the 3rd requ. still doesn't accept it :/ My new code btw:

public class Solution {
    public static void main(String[] args) {
        //write your code here
        String url = new Scanner(System.in).nextLine(), parameters = "", number="";
        String[] urlSplitted = url.split("html?"), partTested = urlSplitted[1].split("&");
        ArrayList<String> strings = new ArrayList<>();
        Double valeur =null;

        for (String part: partTested
             ) {
            if (part.contains("=")){
                String[] temp=part.split("=");
                if (temp[0].charAt(0)=='?') {
                    temp[0]=temp[0].replace("?", "");
                }
                strings.add(temp[0]);
                if ( (Character.isDigit(temp[1].charAt(0)) )){
                    for (char character: temp[1].toCharArray()
                         ) {
                        number+=character;
                    }
                    try {
                        valeur = Double.parseDouble(number);
                    }catch (NumberFormatException e){

                    }
                }

            }else {
                strings.add(part);
            }

        }
        for (String string :
                strings) {
            parameters+= string + " ";
        }

        alert(parameters);
        if (valeur instanceof Double) alert((double)valeur);

    }

    public static void alert(double value) {
        System.out.println(value);
    }

    public static void alert(String value) {
        System.out.println(value);
    }
}

Thomas

Level 41 , Bayreuth, Germany

28 May 2021, 12:08

useful

? has a special meaning for regex so you need to escape it like...

String[] partTested = url.split("\\?")[1].split("&");

otherwise the split won't work correctly, at least the ? remains in the string. As in a URL only one ? is allowed it is sufficient to split at just the ? otherwise you'd need to look for eg. php?, html?, htm?... Now the ? is gone (the regex part above) and you do not need to check for it anymore () lines 12,13 So I sugest you redo your code after if (part.contains("=")) { a little bit. Just split again using =, then you have the parameters name and value, otherwise it's just the value. If the name equals object, remember the value. That's pretty much all. You even won't need to save the results in an array or list directly can output the names. Just the obj value you need to save in a string and later you can check for double etc.

Sansho

Level 19 , Bordeaux, France

28 May 2021, 13:23

Thank you for your new advices! So I've updated my code, I even add the "if "obj" is in url " condition and removed the last ghost space which was added at the end of the string, but that still doesn't validate...

public class Solution {
    public static void main(String[] args) {
        //write your code here
        String url = new Scanner(System.in).nextLine(), parameters = "", number="";
        String[] urlSplitted = url.split("\\?")[1].split("&");//, partTested = urlSplitted[1].split("&");
        ArrayList<String> strings = new ArrayList<>();
        Double valeur =null;

        for (String part: urlSplitted
             ) {
            if (part.contains("=")){
                String[] temp=part.split("=");
                if (temp[0].charAt(0)=='?') {
                    temp[0]=temp[0].replace("?", "");
                }
                strings.add(temp[0]);
                if ( (Character.isDigit(temp[1].charAt(0))) && url.contains("obj")){
                    for (char character: temp[1].toCharArray()
                         ) {
                        number+=character;
                    }
                    try {
                        valeur = Double.parseDouble(number);
                    }catch (NumberFormatException e){
                       // e.printStackTrace();
                    }
                }

            }else {
                strings.add(part);
            }

        }
        for (String string :
                strings) {
            if (strings.indexOf(string) == strings.size()-1) parameters+= string;
            else
                parameters+= string + " ";
        }

        alert(parameters);
        if (valeur instanceof Double) alert(valeur);

    }

    public static void alert(double value) {
        System.out.println("double: " + value);
    }

    public static void alert(String value) {
        System.out.println(value);
    }
}

Thomas

Level 41 , Bayreuth, Germany

28 May 2021, 15:04

useful

OK, a few little things still left to do. First let's take care of the output "String: list of the parameters" That's cause you send the parameters to the alert method. You shouldn't do that, just the obj value you need to send to alert. The parameter names you simply output. And in this task it is not necessary to take care of a trailing space. So it's the best to get rid of that code entirely (everything after the for-each loop you've written). lines 13 and 14 aren't necessary anymore, I already told you that. Split removes the ? So delete these Now delete the entire code inside the if (part.contains("=")) { braces (I know, that looks like deleting nearly everything but you do not need that at all, you probably could write the rest in 10 lines of code). Now imagine the following (we're inside the if contains = braces): If the url part contains a = you split and add index [0], the name, to the list (or just print it). Then check if index [0] equals obj. Yes, save the value in a variable (defined outside the loop of course, initialized to null). Don't forget to add the part to the list (or output it) if the part doesn't contain = Now the code inside the loop is done. Now output the list (if you not opted to print directly) Then check if the temp String variable (holding the obj value) contains a value and if so call alert in a try block, something like that. Just see that as it is, untested pseudo code...

try {
    alert(Double.parseDouble(theTempObjValue));
} catch(NumberFormatException nfe) {
    alert(theTempObjValue);
}

and that's it. You still can optimize that. Eg. you do not necessarily need to check if a URL part contains =. Just split and add part[0] cause if it doesn't contain a = then the result is an array with just on element (index[0]). Then check if there is a second element and if thats length is > 0 if you have the obj name. Done.

Sansho

Level 19 , Bordeaux, France

1 June 2021, 07:25

Thomas you are so Helpful, thanks for it! But even with your advices, the same condition doesn't want to be green... If you can see what's wrong, cuz seriously I'm wondering if it's not a joke atm...

public class Solution {
    public static void main(String[] args) {
        //write your code here
        String url = new Scanner(System.in).nextLine(), parameters = "", number="";
        String[] urlSplitted = url.split("\\?")[1].split("&");
        ArrayList<String> strings = new ArrayList<>();

        for (String part: urlSplitted
             ) {
            if (part.contains("=")){
                String[] partSplitted =part.split("=");
                strings.add(partSplitted[0]);

                if (partSplitted[0].equals("obj")){
                    number= partSplitted[1];
                }

            }else {
                strings.add(part);
            }
        }
        for (String string : strings) {
           parameters+=string + " ";
        }

        alert(parameters);
        try{
            alert(Double.parseDouble(number));
        }catch (NumberFormatException e){
            //alert(number); 4th condition doesn't like it
        }


    }

    public static void alert(double value) {
        System.out.println("double: " + value);
    }
    public static void alert(String value) {
        System.out.println(value);
    }
}

Thomas

Level 41 , Bayreuth, Germany

1 June 2021, 07:57

don't call alert using the parameters as argument just sout the parameters in line 26. Maybe the validator's getting confused with that (means it's checking the alerts parameter and expecting just the obj value)

Sansho

Level 19 , Bordeaux, France

1 June 2021, 08:02

I have to call the alert method (5th condition) :/

Thomas

Level 41 , Bayreuth, Germany

1 June 2021, 10:30

true, but only for the obj value. From the task description: 1. Read a URL from the console. 2. Display a space-delimited list of all the parameters (means just output the parameters) 3. If the obj parameter is present, pass its value to the relevant alert method (self explaining... if there is a obj parameter and that parameter has a value then pass that value to the alert method)