System Namespace   Array Class

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Searches a section of a one-dimensional sorted Array for a value, using the IComparable interface implemented by each element of the Array and by the specified value.

[ VB ]
<Serializable>
Overloads Public Shared Function BinarySearch ( _
   ByVal array As Array, _
   ByVal index As Integer, _
   ByVal length As Integer, _
   ByVal value As Object _
) As Integer

[ C# ]
[Serializable]
public static int BinarySearch (
   Array array,
   int index,
   int length,
   object value
);

[ C++ ]
[Serializable]
public: static int BinarySearch (
   Array* array,
   int index,
   int length,
   Object* value
);

[JScript ]
public Serializable
static function BinarySearch (
   array : Array,
   index : int,
   length : int,
   value : Object
) : int;

array

The one-dimensional Array to search.

index

The starting index of the range to search.

length

The length of the range to search.

value

The object to search for.

The index of the specified value in the specified array, if value is found.

-or-

A negative number, which is the bitwise complement of the index of the first element that is larger than value, if value is not found and value is less than one or more elements in array.

-or-

A negative number, which is the bitwise complement of ( the index of the last element + 1 ) , if value is not found and value is greater than any of the elements in array.

Exception Type	Condition
ArgumentNullException	array is a null reference ( Nothing in Visual Basic ).
RankException	array is multidimensional.
ArgumentOutOfRangeException	index is less than the lower bound of array. -or- length is less than zero.
ArgumentException	index and length do not specify a valid range in array. -or- Neither value nor the elements of array implement the IComparable interface. -or- value is of a type that is not compatible with the elements of array.
InvalidOperationException	The comparer throws an exception.

Either value or every element of array must implement the IComparable interface, which is used for comparisons. If the elements of array are not already sorted in increasing value according to the IComparable implementation, the result might be incorrect.

Duplicate elements are allowed. If the Array contains more than one element with the same value, the method returns only one of the occurrences, and it might return any one of the occurrences, not necessarily the first one.

A null reference ( Nothing in Visual Basic ) can always be compared with any other type; therefore, comparisons with a null reference ( Nothing ) do not generate an exception. When sorting, a null reference ( Nothing ) is considered to be less than any other object.

If the Array does not contain the specified value, the method returns a negative integer. You can apply the bitwise complement operator ( ~ ) to a negative result to produce the index of the first element, if any, that is larger than the specified search value.

Array Members   Array.BinarySearch Overload List   IComparable   Sort

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