File Handling (Cambridge (CIE) A Level Computer Science): Revision Note

Write program code to read the contents of Data.txt into DataArray

Answer

• Opening file Data.txt to read [1 mark]

• Looping through all the 25/EOF … [1 mark]

• … reading each line and storing/appending into array [1 mark]

• Exception handling with appropriate output [1 mark]

• Closing the file (in an appropriate place) [1 mark]

Example program code:

Java

Integer Counter = 0;
try{
    Scanner Scanner1 = new Scanner(new File("Data.txt"));
    while(Scanner1.hasNextLine()){
        DataArray[Counter] = Integer.parseInt(Scanner1.next());
        Counter++;
    }
    Scanner1.close();
}catch(FileNotFoundException ex){
    System.out.println("No data file found");
}

VB.NET

try
  Dim DataReader As New System.IO.StreamReader("Data.txt")
  Dim X As Integer = 0
  Do Until DataReader.EndOfStream
    DataArray(X) = DataReader.ReadLine()
    X = X + 1
  Loop
  DataReader.Close()
Catch ex As Exception
  Console.WriteLine("Invalid file")
End Try

Python

try:
  DataFile = open("Data.txt",'r')
  for Line in DataFile:
    DataArray.append(int(Line))
  DataFile.close()
except IOError:
  print("Could not find file")