What is the role of immutable objects in software development?

Immutable objects play an important role in software development:

• Thread safety: Immutable objects can be freely used in multithreaded environments without synchronization, as their state does not change.
• Predictability: Code with immutable objects is easier to understand and debug, since the object's state does not change after creation.
• Simplified caching and optimization: Immutable objects can be cached and reused without side effects.

In Java, an example of creating an immutable object:

public final class User {
    private final String name;
    private final int age;

    public User(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() { return name; }
    public int getAge() { return age; }
}

Such an object cannot be changed after creation, increasing code reliability.