Help with methods!

[blueandconfused]

I need help with the following java programming assignments...
1. Write a value-returning method, isSVowel, that returns the value true if a given character is a vowel, and otherwise returns false.
2. Write a program that prompts the user to input a sequence of characters and outputs
the number of voweks. (Use the method isVowel written in exercise 1.)
3. Consider the following program segment:
public class Ch7Ex3
{
public static void main(String[] args)
{
int num;
double dec;
.
.
.
}

public static int one(int x, int y)
{
.
.
.
}

public static double two(int x, double a)
{
int first;
double z;
.
.
.
}
}
a. Write the definition of method one so that
it retunrs the sum of x and y if x is greater than y;
otherwise, it should return x minus 2 time y.

b. Write the definition of method two as follows:
i. Read a number and store it in z.
ii. Update the value of z by adding the value of a to its previous value.
iii. Assign the variable first the value returned by method one with the
parameters 6 and 8.
iv. Update the value of first by adding the value of x to its previous value.
v. If the value of z is more than twice the value of first, return z; otherwise, return
2 times first minus z.
c. Write a Java program that tests parts a and b. (Declare additional variables in the method main, if necessary.)

[JGRobinson]

Hi,

Which parts are you having problems with, or don't understand - can you be more specific

[blueandconfused]

Here is what I have for the first one so far. Can you tell me what I am doing wrong and I what I need to do to make it work?
import java.io.*;

public class Vowel
{
static BufferedReader keyboard =
new BufferedReader(new InputStreamReader(System.in));

public static void main(String[] args) throws IOException
{
char ch;

ch = System.out.println("Enter a lowercase letter: ");
System.flush();
isVowel(ch);
}


public static boolean isVowel(String vow)
{
char a, e, i, o, u;
a = 'a';
e = 'e';
i = 'i';
o = 'o';
u = 'u';

if(vow.charAt(a))
return true;
if(vow.charAt(e))
return true;
if(vow.charAt(i))
return true;
if(vow.charAt(o))
return true;
if(vow.charAt(u))
return true;
else
return false;

}

}

[chimaera]

The first thing to get working is your isVowel() method. From the problem, it sounds like isVowel() accepts a char value and determines if this char value is a vowel (i.e. 'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'). This could be implemented as a single if statement:

public static boolean isVowel(char character) {
    if(character == 'a' || character == 'A' ||
       character == 'e' || character == 'E' ||
       character == 'i' || character == 'I' ||
       character == 'o' || character == 'O' ||
       character == 'u' || character == 'U')
        return true;
        
    return false;
}

This should give you a jump start.

The second part of the exercise uses BufferedReader instance (keyboard) that you created. You need to make the call: keyboard.readLine(); to get input from the user.

[blueandconfused]

Thank you for your help. How would I make it so that the method is used in the input/output statements?

[trixma]

Do you want the user to enter input and then display the output? If this is so, you can ask the user to input information by the following code

String input = JOptionPane.showInputDialog("Enter a lowercase letter"); this is quite simple to do.

I don't know where you want to show the output, if u want it to be shown on the console it would look something like this
System.out.println("Lowercase letter entered by the user " + input);
if u wanted it to be shown in a GUI it could look something like this
JTextField field1 = new JTextField(3);
field1.setText(input);

I hope that helps

[blueandconfused]

can you repair this for me please?

public class Exercise1
{
static BufferedReader keyboard =
new BufferedReader(new InputStreamReader(System.in));
public static void main(String[] args)
{
char in;
String inputMessage;
inputMessage = keyboard.ReadLine(in);
inputMessage = System.out.println("Enter a sentence: ");
System.out.flush();

isVowel(in);
}



public static boolean isVowel(char character)
{
if(character == 'a' || character == 'A' ||
character == 'e' || character == 'E' ||
character == 'i' || character == 'I' ||
character == 'o' || character == 'O' ||
character == 'u' || character == 'U')
return true;
else
return false;
}
}

[nspils]

Have you thought about using the Scanner class (new in Java 1.5) instead of buffered reader? I did some assignments using it last quarter and I thought it was easier to use - - more c++ like ...