Hashtable Constructor (Int32, Single, IEqualityComparer)
Initializes a new, empty instance of the Hashtable class using the specified initial capacity, load factor, and IEqualityComparer object.
Assembly: mscorlib (in mscorlib.dll)
Parameters
 capacity

Type:
System.Int32
The approximate number of elements that the Hashtable object can initially contain.
 loadFactor

Type:
System.Single
A number in the range from 0.1 through 1.0 that is multiplied by the default value which provides the best performance. The result is the maximum ratio of elements to buckets.
 equalityComparer

Type:
System.Collections.IEqualityComparer
The IEqualityComparer object that defines the hash code provider and the comparer to use with the Hashtable.
or
null to use the default hash code provider and the default comparer. The default hash code provider is each key's implementation of Object.GetHashCode and the default comparer is each key's implementation of Object.Equals.
Exception  Condition 

ArgumentOutOfRangeException  capacity is less than zero. or loadFactor is less than 0.1. or loadFactor is greater than 1.0. 
Specifying the initial capacity eliminates the need to perform a number of resizing operations while adding elements to the Hashtable object. Capacity is automatically increased as required based on the load factor.
The load factor is the maximum ratio of elements to buckets. A smaller load factor means faster lookup at the cost of increased memory consumption. A load factor of 1.0 is the best balance between speed and size.
When the actual load factor reaches the specified load factor, the number of buckets is automatically increased to the smallest prime number that is larger than twice the current number of buckets.
The IEqualityComparer object includes both the hash code provider and the comparer. If an IEqualityComparer is used in the Hashtable constructor, the objects used as keys in the Hashtable are not required to override the Object.GetHashCode and Object.Equals methods.
The hash code provider dispenses hash codes for keys in the Hashtable. The default hash code provider is the key's implementation of Object.GetHashCode.
The comparer determines whether two keys are equal. Every key in a Hashtable must be unique. The default comparer is the key's implementation of Object.Equals.
The IEqualityComparer enables scenarios such as doing lookups with caseinsensitive strings.
This constructor is an O(n) operation, where n is the capacity parameter.
Available since 10
.NET Framework
Available since 2.0