Question

In java language, use IntelliJ IDEA :

1. Write code that does the following: Opens a file named numberList.txt, uses a for loop to write all the even numbers between 1 and 50 to the file.

2. Write a code that does the following: Opens a file named numberList.txt, uses a for loop to append all the odd numbers between 1 and 50 to the file without deleting the existing data.

Answer 1

Answer 1)

//java io package
import java.io.*;
import java.util.*;
//myClass is class for java program
public class myClass {
    public static void main(String args[]) throws IOException {
        File numF = new File("e:/output1.txt");
        //create a new file
        numF.createNewFile();
        //Writer is used to write integer values in the file
        Writer wr = new FileWriter("e:/output1.txt");
        for(int i=1;i<=50;i++)
            //check whether the number is even
            if (i % 2 == 0) {
                wr.write(i  + " ");
            }
        wr.close();


    }

}

Answer 2)

//java io package
import java.io.*;
import java.util.*;
public class myClass2 {
    public static void main(String args[]) throws IOException {
//FileWriter is used for append
        FileWriter fW = new FileWriter("e:/output1.txt", true);
        //PrintWriter is used to append values in the file
        PrintWriter wr1 = new PrintWriter(fW);
        for(int i=1;i<=50;i++)
            //check whether the number is odd
            if (i % 2 == 1) {
                wr1.print(i  + " ") ;

            }
        wr1.close();


    }
}