Need help with a program

erekose666

I am totally lost here. I need a program to do the following:

write an application that reads a line of text, tokenizes the line using space characters as delimiters and outputs only those words beginning with the letter "b"

I know how to count tokens and whatnot but how the heck do i print out only toeksn beginning with a certain char?

HELP! :)

erekose666

This is the code I have thus far btw:

import java.io.*;
import java.util.*;

public class TokenTest
{
// execute application
public static void main( String args[] )
{
// get sentence
Scanner scanner = new Scanner( System.in );
System.out.println( "Enter a sentence and press Enter" );
String sentence = scanner.nextLine();

// process user sentence
StringTokenizer tokens = new StringTokenizer( sentence);
System.out.printf( "Number of elements: %d\nThe tokens are:\n",
tokens.countTokens() );

while ( tokens.hasMoreTokens() )
System.out.println( tokens.nextToken( ) );
} // end main
} // end class TokenTest

erekose666

I am assuming you have to do something with the charAt function, but I have no idea how to implement it within the program.

r035198x

Quote:

Originally Posted by erekose666

I am assuming you have to do something with the charAt function, but I have no idea how to implement it within the program.

for any string s, s.charAt(0) will return the first character of that String

eg String s = "bless";
s.charAt(0) == 'b' will return true

you could also tokenize the string without using the StringTokenizer

String [] tokens = s.split(" ");

erekose666

OK so let's assume I'm going to use StringTokenizer. How would I fit this into the program as I have coded it thus far?

erekose666

Let me rephrase....I need to return any token that starts with the letter "b", not just the letter "b" itself. :) So from what I'm seeing that you're saying, charAt isn't going to help me at all. Now I'm even more confused than ever lol.

r035198x

Quote:

Originally Posted by erekose666

Let me rephrase....I need to return any token that starts with the letter "b", not just the letter "b" itself. :) So from what I'm seeing that you're saying, charAt isn't going to help me at all. Now I'm even more confused than ever lol.

Expand|Select|Wrap|Line Numbers

 //You misunderstood my post

import java.io.*;

import java.util.*;

public class TokenTest {
 
    public static void main( String args[] ) {
 
        Scanner scanner = new Scanner( System.in );

        System.out.println( "Enter a sentence and press Enter" );

        String sentence = scanner.nextLine();

        int index = 0;
 
        String [] tokens = sentence.split(" ");

        String [] bstart = new String[tokens.length];
 
        System.out.println( "The tokens starting with b are: ");

        for(int i = 0; i < tokens.length; i++) {

            if(tokens[i].charAt(0) == 'b')

                bstart[index++] = tokens[i];

        }
 
        /*

        OR
 
        StringTokenizer st = new StringTokenizer(sentence);

        while(st.hasMoreTokens()) {

            String s = st.nextToken();

            if(s.charAt(0) == 'b') {

                bstart[index++] = s;

            }
 
        */
 
        for(int i = 0; i < bstart.length; i++) {

            System.out.println(bstart[i]);

        }

        //The problem is the null values appended to fill in the array

    }

}

erekose666

OK sorry I did indeed misunderstand :)
That definitely helps me out a lot :)
Thanks so much!

r035198x

Quote:

Originally Posted by erekose666

OK sorry I did indeed misunderstand :)
That definitely helps me out a lot :)
Thanks so much!

If you learn a bit of your regular expressions, you can split the string so that you get only tokens that start with a b.

Need help with a program

re: Need help with a program

re: Need help with a program

re: Need help with a program

re: Need help with a program

re: Need help with a program

re: Need help with a program

re: Need help with a program

re: Need help with a program

Similar Java bytes

/bytes/development

/bytes/it

/bytes/about