C# 面试题与答案
问题 1. What’s the advantage of using System.Text.StringBuilder over System.String?
StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time it’s being operated on, a new instance is created.
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问题 2. Can you store multiple data types in System.Array?
You never use System. Array directly. You can store items whose data type is equivalent to, or derived from, the data type of the array. This means that you can store multiple data types, provided that they derive from a common base type, or implement a common interface.
Example:
If you want to store different types, use System.Collections.ArrayList or object[]
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问题 3. What’s the difference between the System.Array.CopyTo() and System.Array.Clone()?
The first one performs a deep copy of the array, the second one is shallow.
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问题 4. How can you sort the elements of the array in descending order?
By calling Sort() and then Reverse() methods.
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问题 5. What’s the .NET datatype that allows the retrieval of data by a unique key?
HashTable.
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用户评价最有帮助的内容：
- What’s the advantage of using System.Text.StringBuilder over System.String?
- Can you store multiple data types in System.Array?
- What’s the difference between the System.Array.CopyTo() and System.Array.Clone()?
- How can you sort the elements of the array in descending order?
- What’s the .NET datatype that allows the retrieval of data by a unique key?