What are some potential pitfalls to consider when filtering arrays in PHP, especially when dealing with multiple arrays and key-value pairs?

When filtering arrays in PHP, especially when dealing with multiple arrays and key-value pairs, it is important to consider potential pitfalls such as accidentally overwriting values, losing data due to incorrect filtering conditions, and unexpected behavior when using complex filtering logic. To avoid these issues, it is recommended to carefully test the filtering conditions and consider using functions like array_filter() with custom callback functions to ensure accurate filtering. 

// Example of filtering multiple arrays with key-value pairs
$array1 = ['name' => 'John', 'age' => 30];
$array2 = ['name' => 'Jane', 'age' => 25];

// Filtering arrays based on age greater than or equal to 30
$filteredArray1 = array_filter($array1, function($value, $key) {
    return $key === 'age' && $value >= 30;
}, ARRAY_FILTER_USE_BOTH);

$filteredArray2 = array_filter($array2, function($value, $key) {
    return $key === 'age' && $value >= 30;
}, ARRAY_FILTER_USE_BOTH);

print_r($filteredArray1);
print_r($filteredArray2);

Keywords

array_filter array_map array_merge array_key_exists nested arrays

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