Java fixed size list

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Returns a list wrapper with a fixed size, where elements are allowed to be modified, but not added or removed.

FixedSize[ArrayList]

public: static System::Collections::ArrayList ^ FixedSize[System::Collections::ArrayList ^ list]; public static System.Collections.ArrayList FixedSize [System.Collections.ArrayList list]; static member FixedSize : System.Collections.ArrayList -> System.Collections.ArrayList Public Shared Function FixedSize [list As ArrayList] As ArrayList

Parameters

Returns

ArrayList

An ArrayList wrapper with a fixed size.

Exceptions

Examples

The following code example shows how to create a fixed-size wrapper around an ArrayList.

using namespace System; using namespace System::Collections; void PrintValues[ IEnumerable^ myList, char mySeparator ]; int main[] { // Creates and initializes a new ArrayList. ArrayList^ myAL = gcnew ArrayList; myAL->Add[ "The" ]; myAL->Add[ "quick" ]; myAL->Add[ "brown" ]; myAL->Add[ "fox" ]; myAL->Add[ "jumps" ]; myAL->Add[ "over" ]; myAL->Add[ "the" ]; myAL->Add[ "lazy" ]; myAL->Add[ "dog" ]; // Create a fixed-size wrapper around the ArrayList. ArrayList^ myFixedSizeAL = ArrayList::FixedSize[ myAL ]; // Display whether the ArrayLists have a fixed size or not. Console::WriteLine[ "myAL {0}.", myAL->IsFixedSize ? [String^]"has a fixed size" : "does not have a fixed size" ]; Console::WriteLine[ "myFixedSizeAL {0}.", myFixedSizeAL->IsFixedSize ? [String^]"has a fixed size" : "does not have a fixed size" ]; Console::WriteLine[]; // Display both ArrayLists. Console::WriteLine[ "Initially," ]; Console::Write[ "Standard :" ]; PrintValues[ myAL, ' ' ]; Console::Write[ "Fixed size:" ]; PrintValues[ myFixedSizeAL, ' ' ]; // Sort is allowed in the fixed-size ArrayList. myFixedSizeAL->Sort[]; // Display both ArrayLists. Console::WriteLine[ "After Sort," ]; Console::Write[ "Standard :" ]; PrintValues[ myAL, ' ' ]; Console::Write[ "Fixed size:" ]; PrintValues[ myFixedSizeAL, ' ' ]; // Reverse is allowed in the fixed-size ArrayList. myFixedSizeAL->Reverse[]; // Display both ArrayLists. Console::WriteLine[ "After Reverse," ]; Console::Write[ "Standard :" ]; PrintValues[ myAL, ' ' ]; Console::Write[ "Fixed size:" ]; PrintValues[ myFixedSizeAL, ' ' ]; // Add an element to the standard ArrayList. myAL->Add[ "AddMe" ]; // Display both ArrayLists. Console::WriteLine[ "After adding to the standard ArrayList," ]; Console::Write[ "Standard :" ]; PrintValues[ myAL, ' ' ]; Console::Write[ "Fixed size:" ]; PrintValues[ myFixedSizeAL, ' ' ]; Console::WriteLine[]; // Adding or inserting elements to the fixed-size ArrayList throws an exception. try { myFixedSizeAL->Add[ "AddMe2" ]; } catch [ Exception^ myException ] { Console::WriteLine[ "Exception: {0}", myException ]; } try { myFixedSizeAL->Insert[ 3, "InsertMe" ]; } catch [ Exception^ myException ] { Console::WriteLine[ "Exception: {0}", myException ]; } } void PrintValues[ IEnumerable^ myList, char mySeparator ] { IEnumerator^ myEnum = myList->GetEnumerator[]; while [ myEnum->MoveNext[] ] { Object^ obj = safe_cast[myEnum->Current]; Console::Write[ "{0}{1}", mySeparator, obj ]; } Console::WriteLine[]; } /* This code produces the following output. myAL does not have a fixed size. myFixedSizeAL has a fixed size. Initially, Standard : The quick brown fox jumps over the lazy dog Fixed size: The quick brown fox jumps over the lazy dog After Sort, Standard : brown dog fox jumps lazy over quick the The Fixed size: brown dog fox jumps lazy over quick the The After Reverse, Standard : The the quick over lazy jumps fox dog brown Fixed size: The the quick over lazy jumps fox dog brown After adding to the standard ArrayList, Standard : The the quick over lazy jumps fox dog brown AddMe Fixed size: The the quick over lazy jumps fox dog brown AddMe Exception: System.NotSupportedException: Collection was of a fixed size. at System.Collections.FixedSizeArrayList.Add[Object obj] at SamplesArrayList.Main[] Exception: System.NotSupportedException: Collection was of a fixed size. at System.Collections.FixedSizeArrayList.Insert[Int32 index, Object obj] at SamplesArrayList.Main[] */ using System; using System.Collections; public class SamplesArrayList { public static void Main[] { // Creates and initializes a new ArrayList. ArrayList myAL = new ArrayList[]; myAL.Add[ "The" ]; myAL.Add[ "quick" ]; myAL.Add[ "brown" ]; myAL.Add[ "fox" ]; myAL.Add[ "jumps" ]; myAL.Add[ "over" ]; myAL.Add[ "the" ]; myAL.Add[ "lazy" ]; myAL.Add[ "dog" ]; // Create a fixed-size wrapper around the ArrayList. ArrayList myFixedSizeAL = ArrayList.FixedSize[ myAL ]; // Display whether the ArrayLists have a fixed size or not. Console.WriteLine[ "myAL {0}.", myAL.IsFixedSize ? "has a fixed size" : "does not have a fixed size" ]; Console.WriteLine[ "myFixedSizeAL {0}.", myFixedSizeAL.IsFixedSize ? "has a fixed size" : "does not have a fixed size" ]; Console.WriteLine[]; // Display both ArrayLists. Console.WriteLine[ "Initially," ]; Console.Write[ "Standard :" ]; PrintValues[ myAL, ' ' ]; Console.Write[ "Fixed size:" ]; PrintValues[ myFixedSizeAL, ' ' ]; // Sort is allowed in the fixed-size ArrayList. myFixedSizeAL.Sort[]; // Display both ArrayLists. Console.WriteLine[ "After Sort," ]; Console.Write[ "Standard :" ]; PrintValues[ myAL, ' ' ]; Console.Write[ "Fixed size:" ]; PrintValues[ myFixedSizeAL, ' ' ]; // Reverse is allowed in the fixed-size ArrayList. myFixedSizeAL.Reverse[]; // Display both ArrayLists. Console.WriteLine[ "After Reverse," ]; Console.Write[ "Standard :" ]; PrintValues[ myAL, ' ' ]; Console.Write[ "Fixed size:" ]; PrintValues[ myFixedSizeAL, ' ' ]; // Add an element to the standard ArrayList. myAL.Add[ "AddMe" ]; // Display both ArrayLists. Console.WriteLine[ "After adding to the standard ArrayList," ]; Console.Write[ "Standard :" ]; PrintValues[ myAL, ' ' ]; Console.Write[ "Fixed size:" ]; PrintValues[ myFixedSizeAL, ' ' ]; Console.WriteLine[]; // Adding or inserting elements to the fixed-size ArrayList throws an exception. try { myFixedSizeAL.Add[ "AddMe2" ]; } catch [ Exception myException ] { Console.WriteLine["Exception: " + myException.ToString[]]; } try { myFixedSizeAL.Insert[ 3, "InsertMe" ]; } catch [ Exception myException ] { Console.WriteLine["Exception: " + myException.ToString[]]; } } public static void PrintValues[ IEnumerable myList, char mySeparator ] { foreach [ Object obj in myList ] Console.Write[ "{0}{1}", mySeparator, obj ]; Console.WriteLine[]; } } /* This code produces the following output. myAL does not have a fixed size. myFixedSizeAL has a fixed size. Initially, Standard : The quick brown fox jumps over the lazy dog Fixed size: The quick brown fox jumps over the lazy dog After Sort, Standard : brown dog fox jumps lazy over quick the The Fixed size: brown dog fox jumps lazy over quick the The After Reverse, Standard : The the quick over lazy jumps fox dog brown Fixed size: The the quick over lazy jumps fox dog brown After adding to the standard ArrayList, Standard : The the quick over lazy jumps fox dog brown AddMe Fixed size: The the quick over lazy jumps fox dog brown AddMe Exception: System.NotSupportedException: Collection was of a fixed size. at System.Collections.FixedSizeArrayList.Add[Object obj] at SamplesArrayList.Main[] Exception: System.NotSupportedException: Collection was of a fixed size. at System.Collections.FixedSizeArrayList.Insert[int index, Object obj] at SamplesArrayList.Main[] */ Imports System.Collections Public Class SamplesArrayList Public Shared Sub Main[] ' Creates and initializes a new ArrayList. Dim myAL As New ArrayList[] myAL.Add["The"] myAL.Add["quick"] myAL.Add["brown"] myAL.Add["fox"] myAL.Add["jumps"] myAL.Add["over"] myAL.Add["the"] myAL.Add["lazy"] myAL.Add["dog"] ' Create a fixed-size wrapper around the ArrayList. Dim myFixedSizeAL As ArrayList = ArrayList.FixedSize[myAL] ' Display whether the ArrayLists have a fixed size or not. Dim msg As String If myAL.IsFixedSize Then msg = "has a fixed size" Else msg = "does not have a fixed size" End If Console.WriteLine["myAL {0}.", msg] If myFixedSizeAL.IsFixedSize Then msg = "has a fixed size" Else msg = "does not have a fixed size" End If Console.WriteLine["myFixedSizeAL {0}.", msg] Console.WriteLine[] ' Display both ArrayLists. Console.WriteLine["Initially,"] Console.Write["Standard :"] PrintValues[myAL, " "c] Console.Write["Fixed size:"] PrintValues[myFixedSizeAL, " "c] ' Sort is allowed in the fixed-size ArrayList. myFixedSizeAL.Sort[] ' Display both ArrayLists. Console.WriteLine["After Sort,"] Console.Write["Standard :"] PrintValues[myAL, " "c] Console.Write["Fixed size:"] PrintValues[myFixedSizeAL, " "c] ' Reverse is allowed in the fixed-size ArrayList. myFixedSizeAL.Reverse[] ' Display both ArrayLists. Console.WriteLine["After Reverse,"] Console.Write["Standard :"] PrintValues[myAL, " "c] Console.Write["Fixed size:"] PrintValues[myFixedSizeAL, " "c] ' Add an element to the standard ArrayList. myAL.Add["AddMe"] ' Display both ArrayLists. Console.WriteLine["After adding to the standard ArrayList,"] Console.Write["Standard :"] PrintValues[myAL, " "c] Console.Write["Fixed size:"] PrintValues[myFixedSizeAL, " "c] Console.WriteLine[] ' Adding or inserting elements to the fixed-size ArrayList throws an exception. Try myFixedSizeAL.Add["AddMe2"] Catch myException As Exception Console.WriteLine["Exception: " + myException.ToString[]] End Try Try myFixedSizeAL.Insert[3, "InsertMe"] Catch myException As Exception Console.WriteLine["Exception: " + myException.ToString[]] End Try End Sub Public Shared Sub PrintValues[myList As IEnumerable, mySeparator As Char] Dim obj As [Object] For Each obj In myList Console.Write["{0}{1}", mySeparator, obj] Next obj Console.WriteLine[] End Sub End Class ' This code produces the following output. ' ' myAL does not have a fixed size. ' myFixedSizeAL has a fixed size. ' ' Initially, ' Standard : The quick brown fox jumps over the lazy dog ' Fixed size: The quick brown fox jumps over the lazy dog ' After Sort, ' Standard : brown dog fox jumps lazy over quick the The ' Fixed size: brown dog fox jumps lazy over quick the The ' After Reverse, ' Standard : The the quick over lazy jumps fox dog brown ' Fixed size: The the quick over lazy jumps fox dog brown ' After adding to the standard ArrayList, ' Standard : The the quick over lazy jumps fox dog brown AddMe ' Fixed size: The the quick over lazy jumps fox dog brown AddMe ' ' Exception: System.NotSupportedException: Collection was of a fixed size. ' at System.Collections.FixedSizeArrayList.Add[Object obj] ' at SamplesArrayList.Main[] ' Exception: System.NotSupportedException: Collection was of a fixed size. ' at System.Collections.FixedSizeArrayList.Insert[Int32 index, Object obj] ' at SamplesArrayList.Main[]

Remarks

This wrapper can be used to prevent additions to and deletions from the original ArrayList. The elements can still be modified or replaced.

A collection with a fixed size is simply a collection with a wrapper that prevents adding and removing elements; therefore, if changes are made to the underlying collection, including the addition or removal of elements, the fixed-size collection reflects those changes.

This method is an O[1] operation.

FixedSize[IList]

public: static System::Collections::IList ^ FixedSize[System::Collections::IList ^ list]; public static System.Collections.IList FixedSize [System.Collections.IList list]; static member FixedSize : System.Collections.IList -> System.Collections.IList Public Shared Function FixedSize [list As IList] As IList

Parameters

Returns

IList

An IList wrapper with a fixed size.

Exceptions

Remarks

This wrapper can be used to prevent additions to and deletions from the original IList. The elements can still be modified or replaced.

A collection with a fixed size is simply a collection with a wrapper that prevents adding and removing elements; therefore, if changes are made to the underlying collection, including the addition or removal of elements, the fixed-size collection reflects those changes.

This method is an O[1] operation.