Word count problem.

[Avi Chat]

I am having trouble making a java program that reads a document and tells the user how many words there are in the document however it keeps giving me the following error:

 Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String ind
ex out of range: 4
at java.lang.String.charAt(String.java:687)
at search2.main(search2.java:43)
Press any key to continue . . . 

this is what i got so far.

import java.util.*;
import java.io.*;
public class search2
{
public static void main(String[]args) throws IOException
{
char awnChar, contiChar='y';
String awnser, conti, in;
int word=0, sentence=0, vowel=0, consonants=0, digit=0, i=0, length = 0;
Scanner scan = new Scanner(System.in);
//System.out.print("Enter the name of the file: ");
//String fileName = scan.nextLine();
//File file = new File(fileName+".txt");
File file = new File("Quotation.txt");
Scanner input = new Scanner(file);
do
{
System.out.println("What would you like to determine? ");
System.out.println("a.the number of words in the file ");
System.out.println("b.the number of sentences in the file ");
System.out.println("c.the number of vowels in the file ");
System.out.println("d.the number of consonants in the file ");
System.out.println("e.the number of digits (0 - 9) in the file ");
System.out.println();
System.out.print("Input the letter: ");
System.out.println();
awnser = scan.nextLine();
awnChar = awnser.charAt(0);
if(Character.toLowerCase(awnChar) == 'a')
{
while(input.hasNext())
{
in = input.next();
if (in.charAt(i) == ' ')
word++;
i++;
}
System.out.println("There are "+word+" word(s) in that document.");
}
else if (Character.toLowerCase(awnChar) == 'b')
{
while(input.hasNext())
{
in = input.next();
if (in.charAt(i) == '?' || in.charAt(i) == '!' || in.charAt(i) == '.')
sentence++;
i++;
}
System.out.println("There are "+sentence+" sentence(s) in that document.");
}
i = 0;
System.out.println("Would you like to continue? [Y/N] ");
conti = scan.nextLine();
contiChar = conti.charAt(0);
System.out.println();
}while(Character.toLowerCase(contiChar) == 'y');
}
}

Any help appreciated. Thanks.

[Campbell Ritchie]

Welcome to JavaRanch

How are you iterating through the text? You appear to use input.hasNext() as a test in your while loop. You are never doing anything with input in that loop, so that will always return true, until your i variable falls off the end of the String and you suffer a StringIndexOutOfBoundsException.
You will have to use the length of the String to tell whether you need to continue the loop.

[Avi Chat]

Thanks for the prompt reply .

 import java.util.*;
import java.io.*;
public class search2
{
public static void main(String[]args) throws IOException
{
char awnChar, contiChar='y';
String awnser, conti, in, line;
int word=0, sentence=0, vowel=0, consonants=0, digit=0, i=0, length = 0, lengthAll = 0;
Scanner scan = new Scanner(System.in);
//System.out.print("Enter the name of the file: ");
//String fileName = scan.nextLine();
//File file = new File(fileName+".txt");
File file = new File("Quotation.txt");
Scanner input = new Scanner(file);
while(input.hasNext())
{
line = input.nextLine();
length = line.length();
lengthAll = length+lengthAll;
}
do
{
System.out.println("What would you like to determine? ");
System.out.println("a.the number of words in the file ");
System.out.println("b.the number of sentences in the file ");
System.out.println("c.the number of vowels in the file ");
System.out.println("d.the number of consonants in the file ");
System.out.println("e.the number of digits (0 - 9) in the file ");
System.out.println();
System.out.print("Input the letter: ");
System.out.println();
awnser = scan.nextLine();
awnChar = awnser.charAt(0);
if(Character.toLowerCase(awnChar) == 'a')
{
while(lengthAll>i)
{
in = input.next();
if (in.charAt(i) == ' ')
word++;
i++;
}
System.out.println("There are "+word+" word(s) in that document.");
}
else if (Character.toLowerCase(awnChar) == 'b')
{
while(lengthAll>i)
{
in = input.next();
if (in.charAt(i) == '?' || in.charAt(i) == '!' || in.charAt(i) == '.')
sentence++;
i++;
}
System.out.println("There are "+sentence+" sentence(s) in that document.");
}
i = 0;
System.out.println("Would you like to continue? [Y/N] ");
conti = scan.nextLine();
contiChar = conti.charAt(0);
System.out.println();
}while(Character.toLowerCase(contiChar) == 'y');
}
}

Would it be something like that? but i am still getting errors. Still very new at this :S

[Embla Tingeling]

 

Avi Chat wrote:Would it be something like that? but i am still getting errors. Still very new at this :S

This is a common newbie mistake. You take too big a bite and then you end up with a heap of non-working code. Instead always develop programs in small incremental steps. Make sure everything works as expected before moving on. In this way your program will be working from start to finish. This is called Stepwise Refinement and it is the mother of all program development methods.

So start with simple program that just reads a a text file line by line and prints the lines to the screen. Then add functionality litle by little in small working increments.