Repository: TheAlgorithms/Java
File: src/main/java/com/thealgorithms/bitmanipulation/BooleanAlgebraGates.java (Java)

Code before:
package com.thealgorithms.bitmanipulation;

import java.util.List;

/**
 * Implements various Boolean algebra gates (AND, OR, NOT, XOR, NAND, NOR)
 * using Java, generalized to handle multiple inputs.
 */
public final class BooleanAlgebraGates {

    private BooleanAlgebraGates() {
        // Private constructor to prevent instantiation
    }

    /**
     * Interface representing a Boolean gate that takes multiple inputs and returns a result.
     */
    interface BooleanGate {
        boolean evaluate(List<Boolean> inputs);
    }

    /**
     * AND Gate implementation.
     * Returns true if all inputs are true, otherwise false.
     */
    static class ANDGate implements BooleanGate {
        @Override
        public boolean evaluate(List<Boolean> inputs) {
            for (boolean input : inputs) {
                if (!input) {
                    return false;
                }
            }

Review comment (bug):
Looks good, but could you please add tests for this. They should be parametrized. A lot of examples are presented in project.

Possible tests:

```
1. AND Gate Tests:

Basic functionality:
AND([true, true]) should return true.
AND([true, false]) should return false.
AND([false, false]) should return false.

Multiple inputs:
AND([true, true, true]) should return true.
AND([true, false, true]) should return false.

Edge case (empty input list):
AND([]) can either return true (since the conjunction of no values is true in some interpretations) or throw an exception depending on your design.

2. OR Gate Tests:

Basic functionality:
OR([true, false]) should return true.
OR([false, false]) should return false.

Multiple inputs:
OR([true, true, false]) should return true.
OR([false, false, false]) should return false.

Edge case (empty input list):
OR([]) can either return false (since the disjunction of no values is false in some interpretations) or throw an exception.

3. NOT Gate Tests:
4. 
Basic functionality:
NOT(true) should return false.
NOT(false) should return true.

Edge case:
Not applicable, as NOT is a unary operation and requires a single input.

5. XOR Gate Tests:

Basic functionality:
XOR([true, false]) should return true.
XOR([true, true]) should return false.
XOR([false, false]) should return false.

Multiple inputs:
XOR([true, true, true]) should return true.
XOR([true, false, true]) should return false (since the XOR of an odd number of true inputs is true).

Edge case:
XOR([]) can either return false (if no inputs are given) or throw an exception.

7. NAND Gate Tests:

Basic functionality:
NAND([true, true]) should return false.
NAND([true, false]) should return true.
NAND([false, false]) should return true.

Multiple inputs:
NAND([true, true, true]) should return false.
NAND([true, true, false]) should return true.

Edge case:
NAND([]) can either return true or throw an exception depending on your design.

8. NOR Gate Tests:

Basic functionality:
NOR([true, false]) should return false.
NOR([false, false]) should return true.

Multiple inputs:
NOR([false, false, false]) should return true.
NOR([true, true, false]) should return false.

Edge case:
NOR([]) can either return true or throw an exception.

9. Edge Cases and Special Scenarios:

Empty input list:
Test how your program handles cases where an empty list is passed to gates expecting multiple inputs.
If the design assumes an empty list is invalid, it should throw an exception.

Single input for multi-input gates:
AND([true]) should return true.
OR([false]) should return false.
XOR([true]) should return true.

Test how gates behave with a single input as a corner case.

Mixed inputs:
For example, AND([true, false, false, true]) should return false, and similarly for other gates with mixed inputs.

10. Large Input Lists:

AND and OR gates:
Test how they perform with large input lists, e.g., AND([true, true, ..., true]) with 1,000 true values should return true.
Similarly, test OR with a large number of inputs containing mostly false and a single true.

12. Randomized Tests:

Generate random lists of true and false values and validate that the gates work as expected, especially for gates like XOR, which can have less obvious outputs for certain combinations.

13. Behavior on Invalid Input (if applicable):
Test what happens if null is passed as an input list or within the input list. The method should handle this either by throwing an exception or by some defined behavior.
```

Code after:
package com.thealgorithms.bitmanipulation;

import java.util.List;

/**
 * Implements various Boolean algebra gates (AND, OR, NOT, XOR, NAND, NOR)
 */
public final class BooleanAlgebraGates {

    private BooleanAlgebraGates() {
        // Prevent instantiation
    }

    /**
     * Represents a Boolean gate that takes multiple inputs and returns a result.
     */
    interface BooleanGate {
        /**
         * Evaluates the gate with the given inputs.
         *
         * @param inputs The input values for the gate.
         * @return The result of the evaluation.
         */
        boolean evaluate(List<Boolean> inputs);
    }

    /**
     * AND Gate implementation.
     * Returns true if all inputs are true; otherwise, false.
     */
    static class ANDGate implements BooleanGate {
        @Override
        public boolean evaluate(List<Boolean> inputs) {