C# strings are immutable, meaning that once a string object is created, its value cannot be changed. Instead, any operation that modifies a string, such as concatenation or replacement, creates a new string object with the modified value.
One reason for this immutability is that strings are often used as keys in dictionaries or as elements in collections, and immutable objects are more efficient for these uses because their hash code does not change.
Another reason is that strings are often used in multithreaded environments, and immutability allows multiple threads to access the same string object without the risk of data corruption.
Example:
The string which is a reference type stored in a memory heap
Suppose we are creating a string str and assign a value "a";
That will be stored in the memory location like this
Again if we assigning another value to the same string that is "b"
This will not replace the existing value
Instead this will create another memory location like this
This characteristics is called immutable
The memory will grow as you assign new values to the same string
As a memory management best practices if the string is involved in multiple value assignment it's better to use mutable string handle StringBuilder
In summary, C# strings are immutable because it is more efficient for their use cases and it allows them to be used in a safe way in multithreading scenarios.
This concept is also explained in a video here
Comments