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Sorting Data (Visual Basic)

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A sorting operation orders the elements of a sequence based on one or more attributes. The first sort criterion performs a primary sort on the elements. By specifying a second sort criterion, you can sort the elements within each primary sort group.

The following illustration shows the results of an alphabetical sort operation on a sequence of characters.

Graphic that shows an alphabetical sort operation.

The standard query operator methods that sort data are listed in the following section.

Methods

Method Name Description Visual Basic Query Expression Syntax More Information
OrderBy Sorts values in ascending order. Order By Enumerable.OrderBy

Queryable.OrderBy
OrderByDescending Sorts values in descending order. Order By … Descending Enumerable.OrderByDescending

Queryable.OrderByDescending
ThenBy Performs a secondary sort in ascending order. Order By …, … Enumerable.ThenBy

Queryable.ThenBy
ThenByDescending Performs a secondary sort in descending order. Order By …, … Descending Enumerable.ThenByDescending

Queryable.ThenByDescending
Reverse Reverses the order of the elements in a collection. Not applicable. Enumerable.Reverse

Queryable.Reverse

Query Expression Syntax Examples

Primary Sort Examples

Primary Ascending Sort

The following example demonstrates how to use the Order By clause in a LINQ query to sort the strings in an array by string length, in ascending order.

Dim words = {"the", "quick", "brown", "fox", "jumps"}

Dim sortQuery = From word In words
                Order By word.Length
                Select word

Dim sb As New System.Text.StringBuilder()
For Each str As String In sortQuery
    sb.AppendLine(str)
Next

' Display the results.
MsgBox(sb.ToString())

' This code produces the following output:

' the
' fox
' quick
' brown
' jumps

Primary Descending Sort

The next example demonstrates how to use the Order By Descending clause in a LINQ query to sort the strings by their first letter, in descending order.

Dim words = {"the", "quick", "brown", "fox", "jumps"}

Dim sortQuery = From word In words
                Order By word.Substring(0, 1) Descending
                Select word

Dim sb As New System.Text.StringBuilder()
For Each str As String In sortQuery
    sb.AppendLine(str)
Next

' Display the results.
MsgBox(sb.ToString())

' This code produces the following output:

' the
' quick
' jumps
' fox
' brown

Secondary Sort Examples

Secondary Ascending Sort

The following example demonstrates how to use the Order By clause in a LINQ query to perform a primary and secondary sort of the strings in an array. The strings are sorted primarily by length and secondarily by the first letter of the string, both in ascending order.

Dim words = {"the", "quick", "brown", "fox", "jumps"}

Dim sortQuery = From word In words
                Order By word.Length, word.Substring(0, 1)
                Select word

Dim sb As New System.Text.StringBuilder()
For Each str As String In sortQuery
    sb.AppendLine(str)
Next

' Display the results.
MsgBox(sb.ToString())

' This code produces the following output:

' fox
' the
' brown
' jumps
' quick

Secondary Descending Sort

The next example demonstrates how to use the Order By Descending clause in a LINQ query to perform a primary sort, in ascending order, and a secondary sort, in descending order. The strings are sorted primarily by length and secondarily by the first letter of the string.

Dim words = {"the", "quick", "brown", "fox", "jumps"}

Dim sortQuery = From word In words
                Order By word.Length, word.Substring(0, 1) Descending
                Select word

Dim sb As New System.Text.StringBuilder()
For Each str As String In sortQuery
    sb.AppendLine(str)
Next

' Display the results.
MsgBox(sb.ToString())

' This code produces the following output:

' fox
' the
' quick
' jumps
' brown

See also