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Sep 25th, 2008

how to use scanner correctly

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how do i declare a scanner object, filescan publicly so that i may use filescan in varios functions

i found this statement in a forum---->
private static Scanner scanner = new Scanner (1 3 4 4");

when I modified it to----->
public static Scanner filescan = new Scanner(new File("inputdata.txt"));

//declared in the main

i get the following error message
Illegal modifier for parameter scanner; only final is permitted

Thank you guys

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SyLk

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Sep 25th, 2008

Re: how to use scanner correctly

Make it a class level variable - not a public static member.

Ezzaral

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Sep 25th, 2008

Re: how to use scanner correctly

Yes ..
it has to be simply

Quote ...

Scanner filescan = new Scanner(new File("inputdata.txt"));

FYI :

Scanner is from - java.util.Scanner

A simple text scanner which can parse primitive types and strings using regular expressions.

A Scanner breaks its input into tokens using a delimiter pattern, which by default matches whitespace. The resulting tokens may then be converted into values of different types using the various next methods.

For example, this code allows a user to read a number from System.in:

Quote ...

Scanner sc = new Scanner(System.in);
int i = sc.nextInt();

Aashath

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Sep 25th, 2008

Re: how to use scanner correctly

Java Syntax (Toggle Plain Text)
public class praogram1 
{
Scanner scanner  = new Scanner (new File ("t.txt"));
     public static void main(String[] args)
        {
        }
}
public class praogram1 
{
Scanner scanner  = new Scanner (new File ("t.txt"));
     public static void main(String[] args)
        {
        }
}

ok..im tryin to define it at the class level and i run into this issue now. How do i throw an IOException at this level

Default constructor cannot handle exception type FileNotFoundException thrown by implicit super constructor. Must define an explicit constructor

SyLk

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Sep 25th, 2008

Re: how to use scanner correctly

Java Syntax (Toggle Plain Text)
public class Program1 {
 
    Scanner scanner = null;
 
    public Program1(){
        try {
            scanner = new Scanner(new File("t.txt"));
        } catch (FileNotFoundException fe){
            fe.printStackTrace();
        }
    }
 
    public static void main(String[] args) {
 
    }
}
public class Program1 {

    Scanner scanner = null;
    
    public Program1(){
        try {
            scanner = new Scanner(new File("t.txt"));
        } catch (FileNotFoundException fe){
            fe.printStackTrace();
        }
    }

    public static void main(String[] args) {
        
    }
}

Ezzaral

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This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

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