Multiple choice technology programming languages

Which of the following is incorrect about System.Text.StringBuilder and System.String?

  1. StringBuilder is more efficient when there is a large amount of string manipulation

  2. Strings are immutable, so each time a string is changed, a new instance in memory is created.

  3. StringBuilder is mutable; when you modify an instance of the StringBuilder class, you modify the actual string, not a copy

  4. Strings are mutable in .Net
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

System.String is immutable - every operation creates a new string object in memory. StringBuilder is mutable - modifications happen in-place on the same instance. Therefore, the statement "Strings are mutable in .Net" is false, making D the correct choice for the incorrect statement. Options A, B, and C all describe actual differences correctly.

AI explanation

To answer this question, you need to understand the differences between System.Text.StringBuilder and System.String in terms of mutability and efficiency.

Option A) StringBuilder is more efficient when there is a large amount of string manipulation - This option is correct. StringBuilder is designed to be more efficient when there is a need for frequent string manipulation. It provides methods to modify the string without creating a new instance in memory each time.

Option B) Strings are immutable, so each time a string is changed, a new instance in memory is created - This option is correct. System.String objects are immutable, meaning they cannot be changed once created. When you modify a string, a new instance is created in memory.

Option C) StringBuilder is mutable; when you modify an instance of the StringBuilder class, you modify the actual string, not a copy - This option is correct. StringBuilder objects are mutable, meaning they can be modified without creating a new instance. When you modify a StringBuilder object, you modify the actual string it holds.

Option D) Strings are mutable in .Net - This option is incorrect. Strings are immutable in .NET. Once a string is created, it cannot be changed. Any modifications to a string result in the creation of a new string instance in memory.

The correct answer is D) Strings are mutable in .Net. This option is incorrect because strings are actually immutable in .NET.

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