Enumerable.Zip<TFirst, TSecond, TResult> Method

public static IEnumerable<TResult> Zip<TFirst, TSecond, TResult>(
	this IEnumerable<TFirst> first,
	IEnumerable<TSecond> second,
	Func<TFirst, TSecond, TResult> resultSelector
)

Usage Note

The method steps through the two input sequences, applying function resultSelector to corresponding elements of the two sequences. The method returns a sequence of the values that are returned by resultSelector. If the input sequences do not have the same number of elements, the method combines elements until it reaches the end of one of the sequences. For example, if one sequence has three elements and the other one has four, the result sequence has only three elements.

This method is implemented by using deferred execution. The immediate return value is an object that stores all the information that is required to perform the action. The query that this method represents is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.

The following code example demonstrates how to use the Zip<TFirst, TSecond, TResult> method.

int[] numbers = { 1, 2, 3, 4 };
string[] words = { "one", "two", "three" };

// The following example concatenates corresponding elements of the
// two input sequences.
var numbersAndWords = numbers.Zip(words, (first, second) => first + " " + second);
foreach (var item in numbersAndWords)
    Console.WriteLine(item);
Console.WriteLine();

// The following example returns the larger element from each 
// corresponding pair in the input sequences.
int[] numbers2 = { 5, 2, 1, 3, 6 };
var largerElements = numbers2.Zip(numbers,
    (first, second) => first > second ? first : second);
foreach (var item in largerElements)
    Console.WriteLine(item);
Console.WriteLine();

// The following example calculates the commission that is earned by 
// an employee who had sales in the first three quarters of the year.
double[] quarterlySales = { 4023.52, 7701.65, 2435.20 };
double[] quarterlyRate = { 0.25, 0.2, 0.3, 0.2 };
var totalCommission = quarterlySales.Zip(quarterlyRate,
    (first, second) => first * second).Sum();
Console.WriteLine(totalCommission);

// Output:
// 1 one
// 2 two
// 3 three

// 5
// 2
// 3
// 4

// 3276.77

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference