Overload the FailSoftArray indexer : Indexer « Class Interface « C# / C Sharp
Overload the FailSoftArray indexer
/*
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]);
}
}
