C# 0 The Complete Reference

ht

 were obtained and displayed. First, a collection of the keys was 

retrieved by the 

Keys

 property. Each key was then used to index 

ht

, yielding the value 

associated with each key. Remember, the indexer defined by 

IDictionary

 and implemented 

by

Hashtable

 uses a key as the index.

SortedList

SortedList

 creates a collection that stores key/value pairs in sorted order, based on the 

value of the keys. 

SortedList

 implements the 

IDictionary

,

ICollection

,

IEnumerable

, and 

ICloneable

 interfaces.

SortedList

 has several constructors, including those shown here:

public SortedList( )

public SortedList(IDictionary 

c

)

public SortedList(int 

capacity

)

public SortedList(IComparer 

comp

)

The first constructor builds an empty collection with an initial capacity of zero. The second 

constructor builds a 

SortedList

 that is initialized with the elements of 

c

 and has an initial 

capacity equal to the number of elements

.

 The third constructor builds an empty 

SortedList

that has the initial capacity specified by 

capacity.

 The capacity is the size of the underlying 

array that is used to store the elements. The fourth form lets you specify a comparison 

method that will be used to compare the object contained in the list. This form creates an 

empty collection with an initial capacity of zero.

The capacity of a 

SortedList

 grows automatically as needed when elements are added 

to the list. When the current capacity is exceeded, the capacity is increased. The advantage 

of specifying a capacity when creating a 

SortedList

 is that you can prevent or minimize the 

overhead associated with resizing the collection. Of course, it makes sense to specify an 

initial capacity only if you have some idea of how many elements will be stored.

In addition to the methods defined by the interfaces that it implements, 

SortedList

 also 

defines several methods of its own. Some of the most commonly used ones are shown in Table 

24-6. To determine if a