Flattening Nested Arrays in PHP
Introduction to the concept of flattening nested arrays in PHP, its importance, and common scenarios where this technique is useful.
Understanding the Problem
Explanation of the problem statement with a sample nested JSON structure that needs to be flattened into a single array.
Step-by-Step Solution
Initial Setup
- Define the nested JSON structure that we want to flatten.
Recursive Function
- Create a recursive function (
flattenArray) that traverses the nested structure and flattens it into a single array.
- Create a recursive function (
Filtering Based on Condition
- Enhance the function to include filtering based on specific conditions, such as filtering nodes where
is_activeistrue.
- Enhance the function to include filtering based on specific conditions, such as filtering nodes where
Implementation in PHP
- Provide PHP code snippets demonstrating how to implement the
flattenArrayfunction.
- Provide PHP code snippets demonstrating how to implement the
Example Implementation
phpCopy code<?php
// Example JSON data
$jsonData = '{
// Your JSON data here
}';
// Decode JSON data into PHP associative array
$data = json_decode($jsonData, true);
// Function to recursively flatten and filter the array structure
function flattenAndFilterArray($data) {
$result = [];
// Function to recursively process each node
$processNode = function($node) use (&$result, &$processNode) {
if ($node['is_active']) {
$flattenedNode = [
'id' => $node['id'],
'parent_id' => $node['parent_id'],
'name' => $node['name'],
'is_active' => $node['is_active'],
'position' => $node['position'],
'level' => $node['level'],
'product_count' => $node['product_count'],
];
// Recursively process children nodes
foreach ($node['children_data'] as $child) {
$flattenedChild = $processNode($child);
$result[] = array_merge($flattenedNode, $flattenedChild);
}
// If no children, add the current node itself to result
if (empty($node['children_data'])) {
$result[] = $flattenedNode;
}
}
return $flattenedNode ?? [];
};
// Process the top-level nodes
foreach ($data['children_data'] as $node) {
$processNode($node);
}
return $result;
}
// Flatten and filter the array structure
$flattenedAndFilteredArray = flattenAndFilterArray($data);
// Output the flattened and filtered array
echo json_encode($flattenedAndFilteredArray, JSON_PRETTY_PRINT);
?>
for example input is
{
"id": 88,
"parent_id": 1,
"name": "Example.com",
"is_active": true,
"position": 1,
"level": 1,
"product_count": 826,
"children_data": [
{
"id": 201,
"parent_id": 88,
"name": "BREAKFAST",
"is_active": false,
"position": 1,
"level": 2,
"product_count": 6,
"children_data": []
},
{
"id": 236,
"parent_id": 88,
"name": "BREAKFAST",
"is_active": true,
"position": 2,
"level": 2,
"product_count": 81,
"children_data": [
{
"id": 137,
"parent_id": 236,
"name": "Savoury Breakfasts",
"is_active": true,
"position": 1,
"level": 3,
"product_count": 14,
"children_data": []
},
{
"id": 136,
"parent_id": 236,
"name": "Sweet & Healthy Breakfast",
"is_active": true,
"position": 2,
"level": 3,
"product_count": 42,
"children_data": []
},
{
"id": 169,
"parent_id": 236,
"name": "Hot Breakfast ",
"is_active": true,
"position": 3,
"level": 3,
"product_count": 11,
"children_data": []
},
{
"id": 138,
"parent_id": 236,
"name": "Coffee & Tea ",
"is_active": false,
"position": 4,
"level": 3,
"product_count": 3,
"children_data": []
},
{
"id": 135,
"parent_id": 236,
"name": "Water, Soft Drinks & Juices",
"is_active": false,
"position": 5,
"level": 3,
"product_count": 21,
"children_data": []
}
]
},
{
"id": 98,
"parent_id": 88,
"name": "MID MORNING",
"is_active": true,
"position": 3,
"level": 2,
"product_count": 112,
"children_data": [
{
"id": 117,
"parent_id": 98,
"name": "Mini Desserts",
"is_active": false,
"position": 1,
"level": 3,
"product_count": 68,
"children_data": []
},
{
"id": 220,
"parent_id": 98,
"name": "Coffee & Tea ",
"is_active": false,
"position": 2,
"level": 3,
"product_count": 3,
"children_data": []
},
{
"id": 221,
"parent_id": 98,
"name": "Water, Soft Drinks & Juices",
"is_active": false,
"position": 3,
"level": 3,
"product_count": 21,
"children_data": []
}
]
}
]
}
and Desire output is
[
{
"id": 201,
"parent_id": 88,
"name": "BREAKFAST",
"is_active": false,
"position": 1,
"level": 2,
"product_count": 6,
"children_data": []
},
{
"id": 236,
"parent_id": 88,
"name": "BREAKFAST",
"is_active": true,
"position": 2,
"level": 2,
"product_count": 81,
"children_data": []
},
{
"id": 137,
"parent_id": 236,
"name": "Savoury Breakfasts",
"is_active": true,
"position": 1,
"level": 3,
"product_count": 14,
"children_data": []
},
{
"id": 136,
"parent_id": 236,
"name": "Sweet & Healthy Breakfast",
"is_active": true,
"position": 2,
"level": 3,
"product_count": 42,
"children_data": []
},
{
"id": 169,
"parent_id": 236,
"name": "Hot Breakfast ",
"is_active": true,
"position": 3,
"level": 3,
"product_count": 11,
"children_data": []
},
{
"id": 138,
"parent_id": 236,
"name": "Coffee & Tea ",
"is_active": false,
"position": 4,
"level": 3,
"product_count": 3,
"children_data": []
},
{
"id": 135,
"parent_id": 236,
"name": "Water, Soft Drinks & Juices",
"is_active": false,
"position": 5,
"level": 3,
"product_count": 21,
"children_data": []
},
{ "id": 98,
"parent_id": 88,
"name": "MID MORNING",
"is_active": true,
"position": 3,
"level": 2,
"product_count": 112,
"children_data": []
},
{
"id": 117,
"parent_id": 98,
"name": "Mini Desserts",
"is_active": false,
"position": 1,
"level": 3,
"product_count": 68,
"children_data": []
},
{
"id": 220,
"parent_id": 98,
"name": "Coffee & Tea ",
"is_active": false,
"position": 2,
"level": 3,
"product_count": 3,
"children_data": []
},
{
"id": 221,
"parent_id": 98,
"name": "Water, Soft Drinks & Juices",
"is_active": false,
"position": 3,
"level": 3,
"product_count": 21,
"children_data": []
}
]