Impure Method in Java

Impure Method

An impure method is one that does not adhere to the principles of purity. It might:

1. Have Side Effects: It can modify external state or variables, such as changing class-level variables, performing I/O operations, or modifying static variables.

2. Non-Deterministic: The method's output can vary even with the same input values, depending on external factors or states.

3. Depend on External State: It may rely on or interact with external variables, class-level state, or other methods.

Example:

public class Counter {
    private int count = 0;

    public void increment() {
        count++; // Modifies the state of the object
    }

    public int getCount() {
        return count; // Depends on the internal state
    }
}

• Side Effects: The increment method modifies the internal state of the Counter object.
• Non-Deterministic: The output of getCount depends on the history of calls to increment.
• Dependence on External State: The behavior relies on the internal state of the object.