Convert errflag into a property : Properties : Class Interface C# Source Code

    

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Convert errflag into a property. 
 
using System; 
 
class FailSoftArray {  
  int[] a; // reference to underlying array  
  int len; // length of array 
 
  bool errflag; // now private 
   
  // Construct array given its size.  
  public FailSoftArray(int size) { 
    a = new int[size]; 
    len = size;  
  } 
 
  // Read-only Length property. 
  public int Length { 
    get { 
      return len; 
    } 
  } 
 
  // Read-only Error property. 
  public bool Error { 
    get { 
      return errflag; 
    } 
  } 
 
  // This is the indexer for FailSoftArray. 
  public int this[int index] { 
    // This is the get accessor. 
    get { 
      if(ok(index)) { 
        errflag = false; 
        return a[index]; 
      } else { 
        errflag = true; 
        return 0; 
      } 
    } 
 
    // This is the set accessor 
    set { 
      if(ok(index)) { 
        a[index] = value; 
        errflag = false; 
      } 
      else errflag = true; 
    } 
  } 
 
  // Return true if index is within bounds. 
  private bool ok(int index) { 
   if(index >= 0 & index < Length) return true; 
   return false; 
  } 
}  
  
// Demonstrate the improved fail-soft array. 
public class FinalFSDemo {  
  public static void Main() {  
    FailSoftArray fs = new FailSoftArray(5); 
 
    // use Error property 
    for(int i=0; i < fs.Length + 1; i++) { 
      fs[i] = i*10; 
      if(fs.Error)  
        Console.WriteLine("Error with index " + i); 
    } 
 
  } 
}