Part of the 101 LINQ SAMPLES

Learn how to use LINQ in your applications with these code samples, covering the entire range of LINQ functionality and demonstrating LINQ with SQL, DataSets, and XML.

Browse all 101 LINQ Samples

Introduction

This sample shows different uses of Partitioning Operators:

Take - Simple
Take - Nested
Skip - Simple
Skip - Nested
TakeWhile - Simple
TakeWhile - Indexed
SkipWhile - Simple
SkipWhile - Indexed

Building the Sample

Open the Program.cs
Comment or uncomment the desired samples
Press Ctrl + F5

Description

Take - Simple

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This sample uses Take to get only the first 3 elements of the array.

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public void Linq20()
 
{
 
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
 
 
 
    var first3Numbers = numbers.Take(3);
 
 
 
    Console.WriteLine("First 3 numbers:");
 
    foreach (var n in first3Numbers)
 
    {
 
        Console.WriteLine(n);
 
    }
 
}

public void Linq20() 
  
{ 
  
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 
  
  
  
    var first3Numbers = numbers.Take(3); 
  
  
  
    Console.WriteLine("First 3 numbers:"); 
  
    foreach (var n in first3Numbers) 
  
    { 
  
        Console.WriteLine(n); 
  
    } 
  
}

Result

First 3 numbers: 5 4 1

Take - Nested

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This sample uses Take to get the first 3 orders from customers in Washington.

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public void Linq21()
 
{
 
    List<Customer> customers = GetCustomerList();
 
 
 
    var first3WAOrders = (
 
        from c in customers
 
        from o in c.Orders
 
        where c.Region == "WA"
 
        select new { c.CustomerID, o.OrderID, o.OrderDate })
 
        .Take(3);
 
 
 
    Console.WriteLine("First 3 orders in WA:");
 
    foreach (var order in first3WAOrders)
 
    {
 
        ObjectDumper.Write(order);
 
    }
 
}

public void Linq21() 
  
{ 
  
    List<Customer> customers = GetCustomerList(); 
  
  
  
    var first3WAOrders = ( 
  
        from c in customers 
  
        from o in c.Orders 
  
        where c.Region == "WA" 
  
        select new { c.CustomerID, o.OrderID, o.OrderDate }) 
  
        .Take(3); 
  
  
  
    Console.WriteLine("First 3 orders in WA:"); 
  
    foreach (var order in first3WAOrders) 
  
    { 
  
        ObjectDumper.Write(order); 
  
    } 
  
}

Result

First 3 orders in WA: CustomerID=LAZYK OrderID=10482 OrderDate=3/21/1997 CustomerID=LAZYK OrderID=10545 OrderDate=5/22/1997 CustomerID=TRAIH OrderID=10574 OrderDate=6/19/1997

Skip - Simple

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This sample uses Skip to get all but the first 4 elements of the array.

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public void Linq22()
 
{
 
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
 
 
 
    var allButFirst4Numbers = numbers.Skip(4);
 
 
 
    Console.WriteLine("All but first 4 numbers:");
 
    foreach (var n in allButFirst4Numbers)
 
    {
 
        Console.WriteLine(n);
 
    }
 
}

public void Linq22() 
  
{ 
  
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 
  
  
  
    var allButFirst4Numbers = numbers.Skip(4); 
  
  
  
    Console.WriteLine("All but first 4 numbers:"); 
  
    foreach (var n in allButFirst4Numbers) 
  
    { 
  
        Console.WriteLine(n); 
  
    } 
  
}

Result

All but first 4 numbers: 9 8 6 7 2 0

Skip - Nested

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This sample uses Take to get all but the first 2 orders from customers in Washington.

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public void Linq23()
 
{
 
    List<Customer> customers = GetCustomerList();
 
 
 
    var waOrders =
 
        from c in customers
 
        from o in c.Orders
 
        where c.Region == "WA"
 
        select new { c.CustomerID, o.OrderID, o.OrderDate };
 
 
 
    var allButFirst2Orders = waOrders.Skip(2);
 
 
 
    Console.WriteLine("All but first 2 orders in WA:");
 
    foreach (var order in allButFirst2Orders)
 
    {
 
        ObjectDumper.Write(order);
 
    }
 
}

public void Linq23() 
  
{ 
  
    List<Customer> customers = GetCustomerList(); 
  
  
  
    var waOrders = 
  
        from c in customers 
  
        from o in c.Orders 
  
        where c.Region == "WA" 
  
        select new { c.CustomerID, o.OrderID, o.OrderDate }; 
  
  
  
    var allButFirst2Orders = waOrders.Skip(2); 
  
  
  
    Console.WriteLine("All but first 2 orders in WA:"); 
  
    foreach (var order in allButFirst2Orders) 
  
    { 
  
        ObjectDumper.Write(order); 
  
    } 
  
}

Result

All but first 2 orders in WA:
CustomerID=TRAIH OrderID=10574 OrderDate=6/19/1997
CustomerID=TRAIH OrderID=10577 OrderDate=6/23/1997
CustomerID=TRAIH OrderID=10822 OrderDate=1/8/1998
CustomerID=WHITC OrderID=10269 OrderDate=7/31/1996
CustomerID=WHITC OrderID=10344 OrderDate=11/1/1996
CustomerID=WHITC OrderID=10469 OrderDate=3/10/1997
CustomerID=WHITC OrderID=10483 OrderDate=3/24/1997
CustomerID=WHITC OrderID=10504 OrderDate=4/11/1997
CustomerID=WHITC OrderID=10596 OrderDate=7/11/1997
CustomerID=WHITC OrderID=10693 OrderDate=10/6/1997
CustomerID=WHITC OrderID=10696 OrderDate=10/8/1997
CustomerID=WHITC OrderID=10723 OrderDate=10/30/1997
CustomerID=WHITC OrderID=10740 OrderDate=11/13/1997
CustomerID=WHITC OrderID=10861 OrderDate=1/30/1998
CustomerID=WHITC OrderID=10904 OrderDate=2/24/1998
CustomerID=WHITC OrderID=11032 OrderDate=4/17/1998
CustomerID=WHITC OrderID=11066 OrderDate=5/1/1998

TakeWhile - Simple

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This sample uses TakeWhile to return elements starting from the beginning of the array until a number is hit that is not less than 6.

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public void Linq24()
 
{
 
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
 
 
 
    var firstNumbersLessThan6 = numbers.TakeWhile(n => n < 6);
 
 
 
    Console.WriteLine("First numbers less than 6:");
 
    foreach (var n in firstNumbersLessThan6)
 
    {
 
        Console.WriteLine(n);
 
    }
 
}

public void Linq24() 
  
{ 
  
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 
  
  
  
    var firstNumbersLessThan6 = numbers.TakeWhile(n => n < 6); 
  
  
  
    Console.WriteLine("First numbers less than 6:"); 
  
    foreach (var n in firstNumbersLessThan6) 
  
    { 
  
        Console.WriteLine(n); 
  
    } 
  
}

Result

First numbers less than 6:
5
4
1
3

TakeWhile - Indexed

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This sample uses TakeWhile to return elements starting from the beginning of the array until a number is hit that is less than its position in the array.

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public void Linq25()
 
{
 
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
 
 
 
    var firstSmallNumbers = numbers.TakeWhile((n, index) => n >= index);
 
 
 
    Console.WriteLine("First numbers not less than their position:");
 
    foreach (var n in firstSmallNumbers)
 
    {
 
        Console.WriteLine(n);
 
    }
 
}

public void Linq25() 
  
{ 
  
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 
  
  
  
    var firstSmallNumbers = numbers.TakeWhile((n, index) => n >= index); 
  
  
  
    Console.WriteLine("First numbers not less than their position:"); 
  
    foreach (var n in firstSmallNumbers) 
  
    { 
  
        Console.WriteLine(n); 
  
    } 
  
}

Result

First numbers not less than their position: 5 4

SkipWhile - Simple

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This sample uses SkipWhile to get the elements of the array starting from the first element divisible by 3.

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public void Linq26()
 
{
 
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
 
 
 
    var allButFirst3Numbers = numbers.SkipWhile(n => n % 3 != 0);
 
 
 
    Console.WriteLine("All elements starting from first element divisible by 3:");
 
    foreach (var n in allButFirst3Numbers)
 
    {
 
        Console.WriteLine(n);
 
    }
 
}

public void Linq26() 
  
{ 
  
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 
  
  
  
    var allButFirst3Numbers = numbers.SkipWhile(n => n % 3 != 0); 
  
  
  
    Console.WriteLine("All elements starting from first element divisible by 3:"); 
  
    foreach (var n in allButFirst3Numbers) 
  
    { 
  
        Console.WriteLine(n); 
  
    } 
  
}

Result

All elements starting from first element divisible by 3:
3
9
8
6
7
2
0

SkipWhile - Indexed

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This sample uses SkipWhile to get the elements of the array starting from the first element less than its position.

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public void Linq27()
 
{
 
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
 
 
 
    var laterNumbers = numbers.SkipWhile((n, index) => n >= index);
 
 
 
    Console.WriteLine("All elements starting from first element less than its position:");
 
    foreach (var n in laterNumbers)
 
    {
 
        Console.WriteLine(n);
 
    }
 
}

public void Linq27() 
  
{ 
  
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 
  
  
  
    var laterNumbers = numbers.SkipWhile((n, index) => n >= index); 
  
  
  
    Console.WriteLine("All elements starting from first element less than its position:"); 
  
    foreach (var n in laterNumbers) 
  
    { 
  
        Console.WriteLine(n); 
  
    } 
  
}

Result

All elements starting from first element less than its position:
1
3
9
8
6
7
2
0

Source Code Files

Program.cs

101 LINQ Samples

More Information

For more information, see:

Partitioning Data - http://msdn.microsoft.com/en-us/library/bb546164.aspx