Thread: Vowels

Hi,
this is the question:
Your program must accept a String (str) & an Integer(pos), returns true if the character at a given position (pos) is a vowel or false otherwise

Here is my attempt:

import java.util.*;
 
public class VowelPositionFromString {
	//accepts a String (str) & an Integer(pos), returns true if the character at a given position (pos) is a vowel or false otherwise
		public static void main (String[]args){
			Scanner in = new Scanner (System.in);
			String str;
			int pos, letter,letterPosition=0;
			System.out.printf("Enter a string\n");
			str = in.nextLine();
			System.out.printf("Enter an intreger position\n");
			pos = in.nextInt();
 
			for (int i=0; i<str.length(); i++)
			{
				letter= str.charAt(i);
				if (Character.isUpperCase(letter))
				{
					letterPosition =letter - 'A' +1;
					if(letterPosition == pos)
					{
						System.out.printf("True"); 
					}
				}		
				else if (Character.isLowerCase(letter))
				{
					letterPosition =letter - 'a' +1;
					if(letterPosition == pos)
					{
						System.out.printf("True"); 
					}
				}
			}
 
 
		}
}

The issue is that I don't know how to link it to a vowel position.
I was thinking about declaring 2 contants:
1. vowelPositions for uppercase letters
2. vowelPositions for lowercase letters
Then I would know how to incorporate it in the program.


I hope I explained well, please assist.


So far my program returns true if a letter in the string corresponds with the position entered.

take a look in the String class of java String (Java Platform SE 7 ) there is a toLowerCase and toUpperCase method in String class. Character class Character (Java Platform SE 7 ) also have those methods.

That way, you can compare two characters in a case insensitive way.
Example
Character.toLowerCase('A').equals(Character.toLowe rCase('a'))

There is also a method equalsIgnoreCase in String that you can also use for comparison of two strings in a case insensitive way.
You can also use the contains method of String but make sure to use the toLowerCase and toUpperCase method.
Example

String name = "JAVA GIRL";
System.out.println(name.contains("java".toUpperCas e());


as you can see from given examples and methods, there are many ways to do that.

Thank you, I implemented the isLowerCase method well.
However, the program requires comparing the entered position which is an integer to characters in the string that may be vowels.

Here is my updated code:

import java.util.*;
 
public class VowelPositionFromString {
	//accepts a String (str) & an Integer(pos), returns true if the character at a given position (pos) is a vowel or false otherwise
		public static void main (String[]args){
			Scanner in = new Scanner (System.in);
			String str;
			int pos, letter,letterPosition=0;
			System.out.printf("Enter a string\n");
			str = in.nextLine();
			System.out.printf("Enter an intreger position\n");
			pos = in.nextInt();
 
			for (int i=0; i<str.length(); i++)
			{
				//converts all string letters to lower case
				letter= str.toLowerCase().charAt(i);
				letterPosition =letter - 'a' +1;
					if(pos == letterPosition && pos == 1|| 5 || 9 || 15 || 21)
					{
						System.out.printf("True"); 
					}
					else 
					{
						System.out.printf("False"); 
					}
				}		
 
		}
	}

My only problem is the format of the line: if(pos == letterPosition && pos == 1|| 5 || 9 || 15 || 21)
NB: 1,5,9,15, AND 21 are the vowel positions in lowercase so the position entered (pos) must be equal to the letter postion in the string and any one of the vowel positions to be true.

if(pos == letterPosition && pos == 1|| 5 || 9 || 15 || 21)

I am not sure if you have a compilation error with that line. that is not a valid syntax for java 6 and below, I am not sure if you are using java 7 and you compiled that statement successfully.
do you have compilation error?

you can also use the example statement below:
pos == 1 || pos == 2 || pos == 3 .......

1,5,9,15, AND 21 are the vowel positions in lowercase so the position entered (pos) must be equal to the letter postion in the string and any one of the vowel positions to be true.

hmm. but where is the letter or String values that holds that letters? did you declared that a = 1?
or String letters = "abcd....";? actually you can use the ASCII which says that lower case "a" is equal = 97 (in decimal) kindly see the ASCII tables. that will make you code it easily rather than declaring a String that holds the Alphabet.

Hi, I took both the ASCII guidance into condieration

what I changed:

for (int i=0; i<str.length(); i++)
			{
				//converts all string letters to lower case
				letter= str.toLowerCase().charAt(i);
				letterPosition =letter - 'a' +1;
					if(pos == letterPosition) 
					{
						if ( letterPosition == 97|| letterPosition == 101 ||letterPosition ==105 || letterPosition== 111 || letterPosition==117)
						System.out.printf("True"); 
					}
					else if (pos != letterPosition)
					{
						System.out.printf("False"); 
					}
			}

My output:
Enter a string
trend
Enter an intreger position
101
FalseFalseFalseFalseFalse



It just suppose to say True because 101 is e in ASCII :/

nope. try to put of the position of e in your first input trend.

I think It should be like this:
Enter a string
Java Girl -my input
Enter an integer position
1 -my input


if it is base 0, then the letter in position 1 is a and the output should be true.
should it be like that?

Thank you so much for all the guidance everyone! I simplified the program and got it to work just how it is required to work
Here is my solution:

import java.util.*;
 
public class VowelPositionWithinString {
	//accepts a String (str) & an Integer(pos), returns true if the character at a given position (pos) is a vowel or false otherwise
			public static void main (String[]args){
				Scanner in = new Scanner (System.in);
				String str;
				char letter;
				int pos, vowelPosition=0;
				System.out.printf("Enter a string\n");
				str = in.nextLine();
				System.out.printf("Enter an intreger position\n");
				pos = in.nextInt();
 
				for (int i=0; i<str.length(); i++)
				{
					//converts all string letters to lower case
					letter = str.toLowerCase().charAt(i);
                    if (letter == 'a' ||letter == 'e' ||letter == 'i' ||letter == 'o' ||letter == 'u')
                    {
                    	vowelPosition = letter -'a' + 1;
                    	if (vowelPosition == pos)
                    	{
                    		System.out.printf("True");
                    		break;
                    	}
                    	else System.out.printf("False"); 
                    }
 
		}
 
	}
}