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Thread: problem with toString and boolean operator

  1. #1
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    Default problem with toString and boolean operator

    this compiles but i am not getting right output.......this is the output that i was hoping but somehow it is not getting right......can someone help me what is the problem with my code.

    public class Television
    {
    //Instance variables
    private int channel;
    private int volume;
    boolean power = false;
    String[] channelName = {"CBS","FOX","DISCOVERY","PBS","HBO","CNN","DISNEY ","CNN","TBS","USA"} ;


    //No argument constructors
    public Television ()
    {
    this(1,1);

    }

    //Overloaded constructor
    public Television(int ch, int vol)
    {
    setChannel (ch);
    setVolume (vol);
    }

    //Mutator methods
    public void powerOn()
    {
    this.power = true;
    }

    public void powerOff()
    {
    this.power = false;

    }

    public void increaseVolume()
    {
    volume++;
    }


    public void decreaseVolume()
    {
    volume--;
    }

    public void setVolume (int volume)
    {
    if (this.power == true)
    {
    if (volume < 0)
    {
    this.volume = 0;
    }

    if (volume > 10)
    {
    this.volume = 10;
    }
    }
    }

    public void setChannel (int channel)
    {
    if (this.power == true)
    {
    if (channel < 1)
    {
    this.channel = 1;
    }

    if (channel >10)
    {
    this.channel = 10;
    }
    }
    }


    //Accessor methods
    public int getVolume()
    {
    return volume;
    }

    public int getChannel()
    {
    return channel;
    }

    public String[] getChannelName()
    {
    if (this.power == true)
    {

    if (this.channel ==1)
    {
    channelName[0] = "CBS";;
    }
    if (this.channel ==2)
    {
    channelName[1] = "FOX";
    }
    if (this.channel ==3)
    {
    channelName[2] = "DISCOVERY";
    }
    if (this.channel ==4)
    {
    channelName[3] = "PBS";
    }
    if (this.channel ==5)
    {
    channelName[4] = "HBO";
    }
    if (this.channel ==6)
    {
    channelName[5] = "CNN";
    }
    if (this.channel ==7)
    {
    channelName[6] = "DISNEY";
    }
    if (this.channel ==8)
    {
    channelName[7] = "CNN";
    }
    if (this.channel ==9)
    {
    channelName[8] = "TBS";
    }
    if (this.channel ==10)
    {
    channelName[9] = "USA";
    }
    }
    return channelName;
    }


    public String toString()
    {

    return String.format(" TV State: \n Channel No: %d \n Channel Name: %s \n Volume: %d",getChannel(), getChannelName(), getVolume() );
    }
    } //end class



    //television app

    public class TelevisionApp
    {
    public static void main (String[] args)
    {
    Television T1 = new Television(3,5);
    T1.powerOn();

    Television T2 = new Television ();
    T2.powerOn();
    T2.setChannel(4);
    T2.setVolume(10);

    System.out.println (T1.toString());
    System.out.println ("T2 = "+T2);



    }
    }

    //output should be something like this

    TV Status: On
    Channel No: 4
    Channel Name: HBO
    volume : 6


  2. #2
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    Default Re: problem with toString and boolean operator

    What output are you getting instead?

    In future surround your code with code tags to retain formatting and make it easier to read.
    Improving the world one idiot at a time!

  3. #3
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    Default Re: problem with toString and boolean operator

    i am getting
    TV set:
    channel No: 0
    Channel Name: j.lang.String.@4563467
    volume: 0

  4. #4
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    Default Re: problem with toString and boolean operator

    Channel Name: j.lang.String.@4563467

    The getChannelName method returns the entire array and not a single name.
    Improving the world one idiot at a time!

  5. #5
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    Default Re: problem with toString and boolean operator

    I dont know how to return array in toString method

    Also how do i print TV state On using toString method?

  6. #6
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    Default Re: problem with toString and boolean operator

    The toString method is calling the getChannelName method. Why is your getChannelName method returning the whole array of channel names instead of a single channel name?

    BTW you can simplify you getChannelName method to a single line of code.
    Improving the world one idiot at a time!

  7. #7
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    Default Re: problem with toString and boolean operator

    because if the channel number is 1, we want to display channel Name as "CBS". Since there are 10 channels that is why i am returning whole array using if statement. I dont know if that is the right way to do......

  8. #8
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    Default Re: problem with toString and boolean operator

    No!

    You only want to return a single channel name. If the channel is 1 you want it to only return CBS. Doesn't that make sense?
    Improving the world one idiot at a time!

  9. #9
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    Default Re: problem with toString and boolean operator

    I have confusion with array. i thought this will return only one value of array.......so i should write like return channelName[]; ....could you please help me how to return one value of array ?

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    Default Re: problem with toString and boolean operator

    Simple, put a number inside the square brackets.
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  11. #11
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    Default Re: problem with toString and boolean operator

    but channelName is based on channel number. so I cannot put a fixed number.Are you talking about public String[] getChannelName() section? TelevisionApp program is controlling the value. Could you please write the code because I am not getting what you are trying to say........

  12. #12
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    Default Re: problem with toString and boolean operator

    Quote Originally Posted by centralguide View Post
    but channelName is based on channel number.
    Hello!!!!!!
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  13. #13
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    Default Re: problem with toString and boolean operator

    is it wrong?

  14. #14
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    Default Re: problem with toString and boolean operator

    I was pointing out that you answered your own question of what goes inside the square brackets.
    Improving the world one idiot at a time!

  15. #15
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    Default Re: problem with toString and boolean operator

    if I write
    return channelName[channel];

    it gives me compilation error. It says
    required: String[]
    found: String

  16. #16
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    Default Re: problem with toString and boolean operator

    Change the return type of the method. I have been saying all along that method should be returning a String
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