highschool/Grade 10/Computer Science/ICS4U1/Reading And Writing To Files.md

Reading and Outputting Files

Outputing To Files - you can save it for future use - The printwriter class can be used to createa file and wrtie data to it - necessay imports:

import java.io.IOException;
import java.io.PrintWriter;

• Or:

import java.io.*;

• It is declared similarly to the scanner class

Different types of file can be created for data to be written to, depends on the extension eg. “.txt” creates a text file while docsx creates a docx document

code

Reading To Files

• Speed
• Less errors
• Easier to read individual cases
• able to get data from sources other than keyboard
• changing information is easy only to file
• more efficient less time to test
• large amounts of data can be entered quickly
• at the testing stage, data can be easily

How

• The file class is java’s representation of a file or directoy path
• it is used to identify/ocate the file that is to be read
• code
• Scanner calss is used to read from file

Sample Code

import java.util.Scanner;
import java.io.File;
import java.io.IOException;
public class ReadingToFileDemo {
    public static void (String[]args) throws IOException {
        File file = new File("test.txt); // the file you are reading from
        Scanner read = new Scanner(file);
        while(read.hasNext()) {
            System.out.println(read.nextLine());
            read.next();
        }
    }
}