C# 0 The Complete Reference

PART I

C h a p t e r   1 0 :  

I n d e x e r s   a n d   P r o p e r t i e s  

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PART IPART I

    // 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.

class FinalFSDemo {

  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);

    }

  }

}

The creation of the 

Error

 property has caused two changes to be made to 

FailSoftArray

.

First,

ErrFlag

 has been made private because it is now used as the underlying storage for 

the

Error

 property. Thus, it won’t be available directly. Second, the read-only 

Error

 property 

has been added. Now, programs that need to detect errors will interrogate 

Error

. This is 

demonstrated in 

Main( )

, where a boundary error is intentionally generated, and the 

Error

property is used to detect it.