Using Coin Class

[tmlucky14]

I am having trouble getting my Coin Program to run. I think my Coin.java is right, but my Runs.java program will not run. Can you tell me what I am doing wrong.

Using the Coin Class

The Coin class from Listing 5.4 in the text is in the file Coin.java. Copy it to your directory, then write a program to find the length of the longest run of heads in 100 flips of the coin. A skeleton of the program is in the file Runs.java. To use the Coin class you need to do the following in the program:

1. Create a coin object.
2. Inside the loop, you should use the flip method to flip the coin, the toString method (used implicitly) to print the results of the flip, and the getFace method to see if the result was HEADS. Keeping track of the current run length (the number of times in a row that the coin was HEADS) and the maximum run length is an exercise in loop techniques!
3. Print the result after the loop.



//********************************************************************
// Coin.java
//
// Represents a coin with two sides that can be flipped.
//********************************************************************

public class Coin
{
public final int HEADS = 0;
public final int TAILS = 1;

private int face;
private int id;

//-----------------------------------------------------------------
// Sets up the coin by flipping it initially.
//-----------------------------------------------------------------
public Coin (int anID)
{

id = anID;
System.out.println( "** in coin " + id + "'s constructor**" );
flip();
}

//-----------------------------------------------------------------
// Flips the coin by randomly choosing a face.
//-----------------------------------------------------------------
public void flip ()
{
System.out.println( "** in coin " + id + "'s flip **" );
face = (int) (Math.random() * 2);
}

//-----------------------------------------------------------------
// Returns the current face of the coin is head.
//-----------------------------------------------------------------
public int getFace ()
{
System.out.println( "** in coin " + id + "'s getFace **" );
return face;
}

//-----------------------------------------------------------------
// Returns the current face of the coin as a string.
//-----------------------------------------------------------------
public String toString()
{
String faceName;
System.out.println( "\n** in coin " + id + "'s toString **" );
if (face == HEADS)
faceName = "Heads";
else
faceName = "Tails";

return faceName;
}
}
___________________________________________________________-

// ********************************************************************
// Runs.java
//
// Finds the length of the longest run of heads in 100 flips of a coin.
// ********************************************************************

public class Runs
{
public static void main (String[] args)
{
final int FLIPS = 100; // number of coin flips

int currentRun = 0; // length of the current run of HEADS
int maxRun = 0; // length of the maximum run so far

// Create a coin object
Coin myCoin = new Coin();

if(myCoin.toString().equals("Heads"))
{
currentRun++;

if(currentRun > maxRun)
maxRun = currentRun;
}
else
{
currentRun = 0;
}




// Flip the coin FLIPS times
for (int i = 0; i < FLIPS; i++)
{
// Flip the coin & print the result

// Update the run information

}

// Print the results

}
}

[System_Error]

I am having trouble getting my Coin Program to run. I think my Coin.java is right, but my Runs.java program will not run. Can you tell me what I am doing wrong.

What error are you getting?

[eranga262154]

tmlucky14,

Try do put the complete question here. If not it makes lot of difficulties to you as well as for others.

[DeadEyes]

Your Coin constructor expects an int.

[eranga262154]

Your Coin constructor expects an int.

Sorry,

I'm not clear what you are saying.

[DeadEyes]

//this is your constructor which takes an int 
public Coin (int anID)
{

id = anID;
System.out.println( "** in coin " + id + "'s constructor**" );
flip();
}
:
:
//This is how your are creating the object
Coin myCoin = new Coin();
//should perhaps be
Coin myCoin = new Coin(0);

[eranga262154]

Ok,
I got the point. Thanks

[tmlucky14]

I compile the Runs.java and got a error

Runs.java:31: 'else' without 'if'
else
^
//

Can you tell why I am getting this error and if My Coin.java look ok. Thanks

********************************************************************
// Runs.java
//
// Finds the length of the longest run of heads in 100 flips of a coin.
// ********************************************************************
public class Runs
{
public static void main (String[] args)
{

final int FLIPS = 100; // number of coin flips

int currentRun = 0; // length of the current run of HEADS
int maxRun = 0; // length of the maximum run so far

// Create a coin object
Coin myCoin = new Coin();

// Flip the coin FLIPS times
for (int i = 0; i < FLIPS; i++)
{
// Flip the coin & print the result
myCoin.flip();
System.out.println(myCoin);

// Update the run information
if (myCoin.getface() == 0);
{
currentRun = currentRun + 1;
}
else
{
if (currentRun > maxRun);
maxRun = currentRun;

currentRun = 0;
}
}

// Print the results
System.out.println("The maxmimum run is: " + maxRun);
}
}

[TBeck]

if (currentRun > maxRun);

I think they error should go away if you remove the ; from the end of the if line

[tmlucky14]

That went away now, I got another error

Runs.java:34: not a statement
(maxRun = currentRun);
^
1 error

[CornedBee]

The other if has a semicolon, too.
Also, the code line you pointed out does not exist in what you've posted, so please post updated code.

[tmlucky14]

This part of my code is not working. Can you please help me. Thanks

if (currentRun > maxRun)
(maxRun = currentRun);

My error is
Runs.java:34: not a statement
(maxRun = currentRun);
^
1 error

[CornedBee]

Remove the parentheses.

[Tmcclain]

Now this part is not working

// Update the run information
if (myCoin.getface() == 0)

Runs.java:27: cannot resolve symbol
symbol : method getface ()
location: class Coin
if (myCoin.getface() == 0)
^
1 error

[CornedBee]

Java is case-sensitive.

[Tmcclain]

I am new to this so what does that mean and what do u think I should do to fix my problem. Thank

[TBeck]

the .getface() must be .getFace()
it has to be the same capitialization as in the Coin class.