DNF types (Disjunctive Normal Form) in PHP - Mini Project: Build & Apply

DNF types (Disjunctive Normal Form) in PHP

📖 Scenario: Imagine you are building a simple rule checker for a game. The rules are written in a way that combines conditions with AND and OR. This is called Disjunctive Normal Form (DNF). You want to represent these rules in PHP and check if a player's attributes match any of the rules.

🎯 Goal: You will create a PHP program that stores rules in DNF format, sets a player's attributes, checks which rules the player matches, and prints the matching rules.

📋 What You'll Learn

Create an array called $rules that holds multiple rules in DNF format.

Create an associative array called $player with specific attributes.

Write a loop to check each rule against the player's attributes using DNF logic.

Print the indexes of the rules that the player matches.

💡 Why This Matters

🌍 Real World

DNF is used in logic and computer science to simplify complex conditions. This project shows how to represent and check such conditions in code.

💼 Career

Understanding DNF and condition checking is useful for roles in software testing, rule engines, game development, and any job involving complex decision logic.

1

Create the rules array in DNF format

Create an array called $rules with two rules. Each rule is an array of clauses. Each clause is an associative array with keys 'color' and 'size'. Use these exact values: First rule: one clause with 'color' => 'red' and 'size' => 'large'. Second rule: two clauses, first with 'color' => 'blue' and 'size' => 'small', second with 'color' => 'green' and 'size' => 'medium'.

PHP

<?php

// Create the $rules array with the exact DNF structure
// Your code here

Need a hint?

Remember, DNF means OR of ANDs. Each rule is an OR clause, each clause inside is an AND condition.

2

Create the player attributes array

Create an associative array called $player with these exact keys and values: 'color' => 'blue', 'size' => 'small'.

PHP

 'red', 'size' => 'large']
    ],
    [
        ['color' => 'blue', 'size' => 'small'],
        ['color' => 'green', 'size' => 'medium']
    ]
];

// Create the $player array with exact attributes
// Your code here

Need a hint?

Use an associative array with keys 'color' and 'size' exactly as shown.

3

Check which rules the player matches

Write a loop using foreach with variables $index and $rule to iterate over $rules. Inside, write another loop with variables $clauseIndex and $clause to iterate over $rule. For each $clause, check if all keys and values match exactly with $player. If any clause matches, add $index to an array called $matchedRules. Initialize $matchedRules as an empty array before the loops.

PHP

 'red', 'size' => 'large']
    ],
    [
        ['color' => 'blue', 'size' => 'small'],
        ['color' => 'green', 'size' => 'medium']
    ]
];

$player = ['color' => 'blue', 'size' => 'small'];

// Initialize $matchedRules as empty array
// Use foreach loops to check each rule and clause
// Add matching rule indexes to $matchedRules
// Your code here

Need a hint?

Check each clause fully matches the player. If yes, add the rule index to $matchedRules and stop checking that rule.

4

Print the matching rule indexes

Write a print_r statement to display the $matchedRules array.

PHP

 'red', 'size' => 'large']
    ],
    [
        ['color' => 'blue', 'size' => 'small'],
        ['color' => 'green', 'size' => 'medium']
    ]
];

$player = ['color' => 'blue', 'size' => 'small'];

$matchedRules = [];
foreach ($rules as $index => $rule) {
    foreach ($rule as $clause) {
        $match = true;
        foreach ($clause as $key => $value) {
            if (!isset($player[$key]) || $player[$key] !== $value) {
                $match = false;
                break;
            }
        }
        if ($match) {
            $matchedRules[] = $index;
            break;
        }
    }
}

// Print the $matchedRules array
// Your code here

Need a hint?

Use print_r($matchedRules); to show the array of matched rule indexes.