Question

I need help with my computer science 2 lab.

First I am asked to run the following program and check output?

public static void main(String []args) {
String filename= "output.txt";
File file = new File(fileName);
  
try{
FileWriter fileWriter = new FileWriter(file, true);
fileWriter.write("CS2: we finished the lecuter\n");
fileWriter.close();
}catch (Exception e){
system.out.println("your message"+e);
}

String inputfileName = "output.text";
File fileToRead = new File (inputfileName);
try {
Scanner = new Scanner (fileToread);
while(Scanner.hasNextLine()){
String line = scanner.nextLine();
system.out.println(line);
}
}catch(Eception e){
System.out.println("I could not open to the file to read.");
}
}

then Write a java program to read the attached students.txt file line by line. Split each line text using the split() method of String class and display each line details using loop as follows.

Output:

            S.No: 1

First Name: mohamed

            Last Name: ali

            Telephone: 0504123456

            Courses: cs1, cs2, ds3

------------------------------------------------------------------------------

            S.No: 2

First Name: ahmed

            Last Name: hamdi

            Telephone: 0507415985

            Courses: cs1, cs2, ds3

------------------------------------------------------------------------------

            S.No: 3

First Name: kamel

            Last Name: salem

            Telephone: 0503245714

            Courses: cs1

------------------------------------------------------------------------------

            S.No: 4

First Name: Mohsen

            Last Name: Mohamed

            Telephone: 0503245714

            Courses: cs1, cs2

------------------------------------------------------------------------------

students.txt has this inside:

1:mohamed:ali:0504123456:cs1:cs2:ds3

2:ahmed:hamdi:0507415985:cs1:cs2:ds3


3:kamel:salem:0503245714:cs1
4:Mohsen:Mohamed:0503245714:cs1:cs2

Answer 1

check out the solution and do comment if any queries.

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the given program has many errors, Java is case sensitive language so take care upper and lower cases in keywords and identifiers while using them.

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check out the modified program and analyse the tiny differences in the below program.

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

public class TestRecord {
   public static void main(String []args) {
       String filename= "output.txt";
       File file = new File(filename);
       try{
       FileWriter fileWriter = new FileWriter(file, true);
       fileWriter.write("CS2: we finished the lecuter\n");
       fileWriter.close();
       }catch (Exception e){
       System.out.println("your message"+e);
        }
       String inputfileName = "output.txt";
       File fileToRead = new File (inputfileName);
       try {
        Scanner Scanner = new Scanner (fileToRead);
       while(Scanner.hasNextLine()){
           String line = Scanner.nextLine();
           System.out.println(line);
       }
       }catch(Exception e){
       System.out.println("I could not open to the file to read.");
       }
   } // main ends
} // class ends

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Output :

Console output :

File output :

=========================================================================

Code :

Java program to read Students.txt file.

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

public class TestRecord {
   public static void main(String []args) {
       String inputfileName = "students.txt";
       File fileToRead = new File (inputfileName);
       try {
        // file read
       Scanner Scanner = new Scanner (fileToRead);
       // read line by line using loop
       while(Scanner.hasNextLine()){
           String line = Scanner.nextLine();
           // split the line into array of strings
           String[] arr = line.split(":");
           // display the strings accordingly
           System.out.println("\nS.No: " + arr[0]);
           System.out.println("First Name: " + arr[1]);
           System.out.println("Last Name: " + arr[2]);
           System.out.println("Telephone: " + arr[3]);
           System.out.print("Courses: ");
           // except first 4 strings in array, rest are courses
           // so loop starts from 4 till array length and print results
           for(int i=4; i<arr.length; i++)      
           System.out.print(arr[i] + ", ");  
           System.out.println("\n----------------------------");
       }
       }catch(Exception e){
       System.out.println("I could not open to the file to read.");
       }
   } // main ends
} // class ends

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Code :

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Output :