Why is the .NET String Immutable, and When Should I Use StringBuilder Instead?

.Net String's invariance and its reasons

The String class of .NET is immutable, which means that once it is created, its value cannot be changed. This design decision brings many advantages:

Thread security:

Unchanging string Safe safety, because any thread cannot modify its content.
• Compiler Optimization: The compiler can optimize the operation of the immutable string because it knows that their value will not change.
• Memory saving: String String and atomicization can save memory by reusing existing examples instead of creating new examples.
Symbol simplification:
• The equal comparison between the unsatisfactory string is based on its state rather than the logo, making it easier to reason. Concept consistency:
For some entities, such as the date or non -variable type, the invariance is consistent with its conceptual behavior.
• StringBuilder class: solution to variable string
• Although the String class is immutable, the StringBuilder class provides support for variable string. The StringBuilder object can modify and connect efficiently. This type is particularly useful when constructing a large string or performing complex string operations.
Other advantages of non -degeneration:

Sharing internal status:

Inconsistent objects can share the internal state without causing data damage risk.

Quick replication:

Copy the immutable object is simple and efficient, because there is only one version that needs to be copied.

Although unknown has its advantages, it should be noted that variability is needed in some cases. In this case, alternative technology such as copying when writing can balance between efficiency and flexibility.

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