Method Where

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Where<TSource>(IEnumerable<TSource>, IEnumerable<bool>)

Filters a sequence of values based on an enumeration of boolean values

Declaration
public static IEnumerable<TSource> Where<TSource>(this IEnumerable<TSource> source, IEnumerable<bool> filter)
Parameters
Type Name Description
IEnumerable<TSource> source

An IEnumerable<T> to filter.
IEnumerable<bool> filter

An IEnumerable<T> of boolean values identifying which elements of source to keep.
Returns
Type Description
IEnumerable<TSource>

An IEnumerable<T> that contains elements from the input sequence where the matching value in filter is true.
Type Parameters
Name Description
TSource

The type of the elements of source.
Examples

The following code example demonstrates how to create filter a sequence with matching bool values using Where.

var sequence = Enumerable.Range(1, 5);

// Filter a sequence based on a matching sequence of bools
var result = sequence
    .Where([true, false, true, true, false]);

Console.WriteLine(
    "[" +
    string.Join(", ", result) +
    "]");

// This code produces the following output:
// [1, 3, 4]
Exceptions
Type Condition
ArgumentNullException

source or filter is null.