This course will be retired on July 14, 2025.
- Getting to Know the BirdWatcher Data 2:17
- How Much Data Do We Have? 6:25
- Operators Review 3 questions
- Sightings of Endangered Birds 7:11
- Bird Importing 8:40
- Bird Search Extension 11:44
- Bird Search In Action 7:45
- Extension Method 2 objectives
- Which is Faster? Union versus Concat 6:57
- Some Final Advice 3:15
- Final Advice 3 questions
Quiz Question 1 of 3
The `DefaultIfEmpty` LINQ operator is used to
Choose the correct answer below:
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A
Correlate the elements of two sequences based on key equality, and group the results.
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B
Return elements from a sequence as long as a specified condition is true, and then skips the remaining elements.
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C
Return the elements of the specified sequence or the type parameter's default value in a singleton collection if the sequence is empty.
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D
Return the last element of a sequence, or a default value if no element is found.