String Program

[Sam Pauken]

Can someone help me through this please? I know this is incomplete, and probably a mess, but I have no idea how to finish or fix this.

/*Write a class named Quote with a single instance variable named quote that is a String. 
 *  Write the no-argument and full constructor and the getter and setter.   
 *  
 *   The class should also have methods returns the following:
ï	a. The number of characters in the quote
ï	b. The quote in all uppercase letters
ï	c. The quote in all lowercase letters
ï	d. The first character in the quote
ï	e. the number of vowels in the string 
ï	f. the number of consonants in the string.
ï	g. A method that asks the user to enter a character. 
The program should count and return the number of times that the specified character appears in the string.

*/
public class Quote {
	
	public String quote;
	
	public Quote()
	{
		
	}
	
	public Quote(String q)
	{
		quote = q;
	}
	//put in instance variable and constructors here
	
	//put your getter and setter at the bottom
	
	
	
	// The following are called stub methods.  They essentially have the signature and a set of braces.
	// To avoid red Xs, there is a place holder return line (I am returning the data type that I promised in the signature
	// remove these lines after you add your code.
	
	//NOTE: Look at the UML diagram for the class (in the Module Specific Goodies in the sample output).  
	// Study how my signatures below match the UML diagram for the methods.
	
	//a. The number of characters in the quote
	public int numChars(){
		
		return quote.length();
	}
	
	//b. The quote in all uppercase letters
	public String upper() {
		
		return quote.toUpperCase();
	}
	
	//The quote in all lowercase letters
	public String lower() {
		
		return quote.toLowerCase();
	}
	
	//d. The first character in the quote
	public char firstChar(){
		
		return quote.charAt(0);
	}
	
	//e. the number of vowels in the string
	public int numVowels() {
		
		int vowel = 0;
		
				
		
		
		
		
		return numVowels();
	}
	
	//f. the number of consonants in the string.
	public int numCons() {
		
		int cons = 0;
		
		
		
		return numCons();
		
	}
	
	//g. A method that asks the user to enter a character. 
	//The program should count and return the number of times that the specified character appears in the string.
	public int numTimes(char what){
		// you code this
		return 0;
			
	}

	public String getQuote() {
		return quote;
	}

	public void setQuote(String quote) {
		this.quote = quote;
	}

}

For this class file, I'm having trouble figuring how to code items e-g (ln. 67-94)

ublic class QuoteDriver {

	public static void main(String[] args) {
		
		Scanner scan = new Scanner(System.in);
		
		String quote;
		Quote myQuote;
		
		System.out.println("Give me a quote to analyze.");
		String quote = scan.nextLine();
		Quote myQuote = new Quote(quote);
		// ask the user for a quote.  Store it in a String named quote.  
		// Create an instance of the Quote class calling the full constructor.  Name the instance myQuote.

		int choice = 0;
		while (choice != 999) {
			choice = menu();
			if (choice ==999) {
				System.out.println("Thanks for playing my game!");
				System.exit(0);
			}
			else if (choice ==8){
				System.out.println("Give me a new quote to analyze");
				String quote = scan.nextLine();
				Quote myQuote = new Quote(quote);
				// ask for a new quote. Store it in a String named quote.  
				// Create an instance of the Quote class calling the full constructor.  Name the instance myQuote.
			}
			else if (choice==1) {
				System.out.println("The number of characters in the quote is "+ myQuote.numChars() );
			}
			else if (choice==2) {
				System.out.println("The quote in all upper case is "+ myQuote.upper() );
			}
			else if (choice==3) {
				System.out.println("The quote in all lower case is "+ myQuote.lower() );
			}
			else if (choice==4) {
				System.out.println("The first character of the quote is "+ myQuote.firstChar() );
			}
			else if (choice==5) {
				System.out.println("The number of vowels in the quote is "+ myQuote.numVowels() );
			}
			else if (choice==6) {
				System.out.println("The number of consanants in the quote is "+ myQuote.numCons() );
			}
			else if (choice==7) {
				System.out.println("What character are you looking for?");
				String stWhich = scan.nextLine();
				char which = stWhich.charAt(0);
				System.out.println("The number of times the character '" + which + "' occurs in the quote is "+ myQuote.numTimes(which) );
			}

		}

	}

	public static int menu() {
		Scanner scan = new Scanner(System.in);
		System.out.println("\n Which of the following would you like:");
		System.out.println("1.  The number of characters in the quote");
		System.out.println("2.  The quote in all uppercase letters");
		System.out.println("3.  The quote in all lowercase letters");
		System.out.println("4.  The first character in the quote");
		System.out.println("5.  The number of vowels in the string");
		System.out.println("6.  The number of consonants in the string");
		System.out
				.println("7.  To count the number of occurrences of a specific character in the string");
		System.out.println("8.   Enter an new string");
		System.out.println("999.  Quit the program");

		System.out.println("CHOICE:");
		int choice = scan.nextInt();
		return choice;

	}

}

Here, I'm having trouble declaring my objects and Strings (ln 26-27, 40, 41). You'll see in the comments that we are to call these by the same name in both places, which is complicating things for me.

[Jeanne Boyarsky]

Let's start with one. numVowels(). You have an instance variable called "quote." And you need to figure out how many vowels are in it. Forget about Java for a moment. Suppose you had to explain to a pre-schooler how to find the vowels in a list of letters. You can assume the pre-schooler knows the alphabet and how to count, but not what a vowel is.

First question: how would you explain to the pre-schooler which letters are vowels?
Second question: try to explain in words the algorithm. in particular, look at each letter in time and keep track of what?

You can even post the answers here if you are still struggling or even just for fun Then try to translate what you describe to Java code. See how far you can get implementing this algorithm and post back here with the code you write that doesn't compile/doesn't quite meet your algorithm.

Good luck! I look forward to seeing your questions as you progress though the problem.

[Sam Pauken]

Well, I would first say that a vowel is an a, e, i, o, or a u. So in psuedocode:

vowels=0 //We have zero vowels at the begining
if ("a", "e", "i", "o", or "u") //If it's a vowel
vowels++ //Increment the counter

And keep going till you reach the end of the String. The trick is how to code this.

[Jeanne Boyarsky]

Sam Pauken wrote:Well, I would first say that a vowel is an a, e, i, o, or a u. So in psuedocode:

vowels=0 //We have zero vowels at the begining
if ("a", "e", "i", "o", or "u") //If it's a vowel
vowels++ //Increment the counter

And keep going till you reach the end of the String. The trick is how to code this.

This algorithm is good. I'd add a more explicit loop to your instructions:
vowels=0 //We have zero vowels at the beginning as that makes it easier to see what needs doing.
for each letter in the quote:
if ("a", "e", "i", "o", or "u") //If it's a vowel
vowels++ //Increment the counter

Next step is to translate each line of this code to Java. vowels++ is done already . And line 1 is really close.

Same deal. Try to translate the lines to Java and post what specifically you are stuck on. I'm sure you can translate line 1. For the if statement, look at charAt in the String class

[Sam Pauken]

Ok, here's what I have for finding vowels.

	public int numVowels() {
		
		int vowel = 0;
		for (int i=0; i<quote.length();i++ )
		if (quote.charAt(i)=='a' || quote.charAt(i)=='e' || quote.charAt(i)=='i' ||
			quote.charAt(i)=='o' || quote.charAt(i)=='u')	
			vowel++;
		return numVowels();
	}

For finding consonants, I think it's best to do a "If not a vowel", add them up.

	public int numCons() {
		
		int cons = 0;
		for (int i=0; i<quote.length();i++ )
		if (quote.charAt(i)!='a' || quote.charAt(i)!='e' || quote.charAt(i)!='i' ||
				quote.charAt(i)!='o' || quote.charAt(i)!='u')	
		cons++;
		return numCons();
		
	}

>

I guess point "g" is next.

[Jeanne Boyarsky]

Almost. Look at the return statement. Right now it calls the method again. Which will go on until your computer runs out of memory. Instead you need to return the variable in which you are storing the count.

For consonants, your approach is fine. There's also a clever way of doing it. Think about the relationship between the length of the string, the # of vowels and the # of consonants.

And thanks for bearing with the questions/iterations/subtle clues. You'll learn more and become a better programmer that way than if I gave the full answer.

[Sam Pauken]

Here's what I have so far. I don't really know how to input a character. I just found what I have on line 4 on the internet. IF you could help me through that, that would be great. As for searching the String for the characters and adding them up, I'm a little stumped

	public int numTimes(char what){
		
		System.out.println("Enter a character.");
		char c = scan.findInLine(".").charAt(0);
		
		return 0;
			
	}

[Sam Pauken]

So the other way is "Add up all character - vowels = consonants"?

[Jeanne Boyarsky]

Sam Pauken wrote:So the other way is "Add up all character - vowels = consonants"?

Right. It's less duplicate code which is more important on the job. And add up all the characters is just the length method so the whole thing becomes one line.

[Jeanne Boyarsky]

Sam Pauken wrote:Here's what I have so far. I don't really know how to input a character.

If you are allowed to use Java 7, it's easy. Scanner.console().readLine(). That returns a String but you already know how to get the first character of the line out of a string.

If you aren't allowed to use Java 7, you'd need to use System.in and get a reader that way. I think you'd be allowed to use Java 7, so I'm going to skip looking it up. (It's amazing how fast one forgets the "old ways.")

[Sam Pauken]

I think I'm missing something. I'm getting a "Method undefined for type Scanner" for console(). (I'm using Java 7 v 40).

	public int numTimes(char what){
		
		System.out.println("Enter a character.");
		char c = Scanner.console().readLine();
		

		return 0;
			
	}

[Jeanne Boyarsky]

Sorry. System.console().

[Sam Pauken]

I'm still getting the red Xs.

[Jeanne Boyarsky]

It's should be a different reason now though. You have to choose whether to catch it or throw it.

[Sam Pauken]

I'm sorry. I'm new to this. What is catching and throwing? What does this look like written out?

[Sam Pauken]

OK, I got this for inputting a character.

	public int numTimes(char what){
		
		int numC=0;
		
		System.out.println("Enter a character.");
		String strType = scan.nextLine();
		char c = strType.charAt(0);
		
		for (c=0; c<quote.length(); c++)
			if (quote.charAt(c)=='c') 
				numC=numC+c;

		return numC;
			
	}

Any idea what might be going on in my driver? (Explanation in initial post.)>

[Jeanne Boyarsky]

I hadn't read the initial post in full (the driver part.) Knowing you have a scanner available, I agree that is better to use that. I'm not seeing how the numTimes method compiles (it doesn't appear to have the scanner passed to it.)

More importantly, I don't think that method is supposed to be inputting the character now that I reflect. I think it is supposed to just count instances of the character "what" in the quote. The driver seems to handle all input/output.

As far as the algorithm goes, this doesn't do the right thing. charAt takes the position in the string you care about. See your vowel method. And 'c' is a hard coded value. (That's the one I think needs to be "what")
if (quote.charAt(c)=='c')

I'm not sure what you are asking about the driver. Can you elaborate?

[Sam Pauken]

Like this?

	public int numTimes(char what){
		
		int numC=0;
		
		System.out.println("Enter a character.");
		String strType = scan.nextLine();
		char c = strType.charAt(0);
		
		for (c=0; c<quote.length(); c++)
			if (quote.charAt(c)==what) 
				numC++;

		return numC;	
	}

For the driver, I'm supposed to create and instance of the String class and a Quote object in two different places. In both instances, I have to call the Strings and Quotes by the same name. I don't know how to accomplish this.>

[Campbell Ritchie]

Are you using nextLine after a previous nextLine call? If you call nextLine after nextAnythingElse, it may not work. You may in that instance suffer an out of bounds exception

[Sam Pauken]

Nope, at least I don't think so.

[Jeanne Boyarsky]

Closer. What I'm saying is that I don't think you need these two lines in that method at all.

String strType = scan.nextLine();
char c = strType.charAt(0);

[Sam Pauken]

Yeah, I found that and fixed it. Thanks!

[Warren Lucero]

Sam Pauken wrote:Yeah, I found that and fixed it. Thanks!

I know this post is a couple years old but thanks for posting. I had a similar issue with my code.

[Campbell Ritchie]

Welcome to the Ranch

What was the problem? It is good to see that three‑year‑old threads are still useful.

[Warren Lucero]

Similar issue to Sam's question. I believe I am taking the same course that Sam took a few years ago because the example was similar. Very new to the discussion board and java coding. I am stuck on another assignment. How do I post a question?

[Fred Kleinschmidt]

Instead of checking for a, and e, and i, etc. in a loop, you might consider creating a String VOWELS="AEIOUaeiou" and investigating what methods of String exist to see if a string contains a character.

[Warren Lucero]

Got it working. Thanks