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Thread: Difficulty searching element in an Array

  1. #1
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    Default Difficulty searching element in an Array

    Been messing around for hours and eventually decided to seek the assistance of the internet.

    I am trying to make a program where I/the user can add elements into an array (Name, age gender). Once elements have been added to the array, I want to then be able to search a String (name) to find the desired name I am after in the array. The context of the program is adding Climbers to a Climber Database (just an array) of who has climbed what mountain (haven't attempted adding the mountain stuff yet).

    In what I've written so far, I keep getting the return null, saying that the searched String cannot be found. I have a feeling that I am failing to pass the parameters of the added element in the array.
    For example, I add a 'climber' with the name John, 19, Male in the Climber Class. I then go to the ClubStats class to getClimber and search "John", the only one in the array and I receive a null..

    FYI I am using BlueJ here so at a serious basic level.

    /**
     * Write a description of class Climber here.
     *
     * @author (your name)
     * @version (a version number or a date)
     */
    public class Climber
    {
        // Instance variables.
        // The climber name.
        private String name;
        // The climber age.
        private int age;
        // The climber gender.
        private String gender;
     
        /**
         * Constructor for objects of class Climber
         */
        public Climber(String newName, int newAge, String newGender)
        {
            // Initialise instance variables.
            name = newName;
            age = newAge;
            gender = newGender;
        }
     
        /**
         * Accessor method for climber's name.
         */
        public String getName()
        {
            return name;
        }
     
        /**
         * Set the climber's name.
         */
        public void setName(String newName)
        {
            name = newName;
        }
     
        /**
         * Accessor method for climber's age.
         */
        public int getAge()
        {
            return age;
     
        }
     
        /**
         * Set the climber's age.
         */
        public void setAge(int newAge)
        {
            age = newAge;
     
        }
     
         /**
         * Set the climer's gender.
         */
       public String getGender()
       {
           return gender;
       } 
     
       /**
         * Accessor method for climber's gender.
         */
        public void getGender(String newGender)
        {
            gender = newGender;
     
        }
     
    }
     
    import java.util.ArrayList;
    /**
     * Write a description of class ClubStats here.
     *
     * @author (your name)
     * @version (a version number or a date)
     */
    public class ClubStats
    {
        // An ArrayList for storing climber details.
        private ArrayList<Climber> climber;
        // An ArrayList for storing mountain details.
     
        /**
        * Constructor for objects of class ClubStats
        */
        public ClubStats()
       {
           // Initialise instance variables.
           climber = new ArrayList<Climber>();
     
        }
     
        public void addClimber(Climber newName)
        {
            climber.add(newName);
        }
     
       public Climber getClimber(String name)
       {
           Climber foundClimber = null;
           int index = 0;
           boolean searching = true;
     
           while(searching && index < climber.size()) {
               Climber newName = climber.get(index);
               if(newName.equals(name)) {
                       searching = false;
                       foundClimber = newName;
                    }
                    else {
                        System.out.println(name + " not found");
               [CODE]
    index++;
    }
    }
    return foundClimber;
    }
    }

    [/CODE]

  2. #2
    Member
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    Apr 2014
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    Default Re: Difficulty searching element in an Array

    Hi,

    Your 'newName" variable is not a String object, it's a Climber object. What you need is to compare the climber's name to the passed in name.

    I also strongly suggest renaming your 'climber' array list to 'climbers' - it's a good convention to use plural when naming lists or arrays.

    Climber climber = climbers.get(index);
    if (climber.getName().equals(name)) {
        // Found!
    }
    Good luck!

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