Overload the FailSoftArray indexer : Indexer : Class Interface C# Source Code

    

/*
C#: The Complete Reference 
by Herbert Schildt 

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

// Overload the FailSoftArray indexer. 
  
using System;  
  
class FailSoftArray {   
  int[] a;    // reference to underlying array   
  
  public int Length; // Length is public  
  
  public bool errflag; // indicates outcome of last operation  
    
  // Construct array given its size.  
  public FailSoftArray(int size) {  
    a = new int[size];  
    Length = size;   
  }  
  
  // This is the int 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;  
    }  
  }  
  
  /* This is another indexer for FailSoftArray. 
     This index takes a double argument.  It then 
     rounds that argument to the nearest integer 
     index. */  
  public int this[double idx] {  
    // This is the get accessor.  
    get {  
      int index; 
 
      // round to nearest int 
      if( (idx - (int) idx) < 0.5) index = (int) idx; 
      else index = (int) idx + 1; 
 
      if(ok(index)) {  
        errflag = false;  
        return a[index];  
      } else {  
        errflag = true;  
        return 0;  
      }  
    }  
  
    // This is the set accessor  
    set {  
      int index; 
 
      // round to nearest int 
      if( (idx - (int) idx) < 0.5) index = (int) idx; 
      else index = (int) idx + 1; 
 
      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 fail-soft array.  
public class FSDemo1 {   
  public static void Main() {   
    FailSoftArray fs = new FailSoftArray(5);  
  
    // put some values in fs 
    for(int i=0; i < fs.Length; i++) 
      fs[i] = i;  
 
    // now index with ints and doubles 
    Console.WriteLine("fs[1]: " + fs[1]); 
    Console.WriteLine("fs[2]: " + fs[2]); 
 
    Console.WriteLine("fs[1.1]: " + fs[1.1]); 
    Console.WriteLine("fs[1.6]: " + fs[1.6]); 
 
  }  
}