101 LINQ Samples: Partitioning Operators

Take - Simple

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

     
       
 
        
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

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

     
       
 
        
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

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

     
       
 
        
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

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

     
       
 
        
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

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.

     
       
 
        
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

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.

     
       
 
        
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

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

     
       
 
        
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

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

     
       
 
        
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