Why are strings considered immutable in programming?

Strings are considered immutable in programming primarily to avoid security risks and maintain reference integrity. When a string is immutable, it means that once it is created, it cannot be altered. This characteristic ensures that if a string is shared or referenced in multiple parts of a program, it remains unchanged.

This immutability enhances security by preventing any unintended modifications to sensitive information, such as passwords or identifiers that should remain constant throughout a program's execution. If strings were mutable, any function or method could potentially alter a string's content, leading to unpredictable behavior and vulnerabilities in the software.

Additionally, maintaining reference integrity means that when a string reference is passed around in a program, all references point to the same, unchangeable string. This reduces the risk of bugs arising from changing data unexpectedly in different parts of the application. Therefore, the design choice to make strings immutable promotes better data integrity and security in programming practices.