In PHP, the hash table is the fastest in retrieving, searching, and deleting elements, but the array is the fastest when adding elements; the associative array requires ordered access and is faster than the hash table when adding elements, but Slower in other operations.
Performance comparison between different PHP data structures
In PHP development, choose the appropriate data structure for the application Performance is critical. This article will compare the performance of several common data structures in PHP and provide practical cases to verify the conclusions.
Data structure
- Array (indexed array)
- Associative array (associative array)
- Hash table ( hash table)
Performance standards
- Retrieve a single element
- Find a specific element
- Add a new element
- Delete element
Practical case
Retrieve a single element
$array = range(1, 100000); $key = 50000; // 数组(非有序) $start_time = microtime(true); $value = $array[$key]; $elapsed_time = microtime(true) - $start_time; echo "Indexed array: $elapsed_time seconds\n"; // 关联数组(有序) $array = array_flip($array); $start_time = microtime(true); $value = $array[$key]; $elapsed_time = microtime(true) - $start_time; echo "Associative array: $elapsed_time seconds\n"; // 哈希表 $hash = []; foreach ($array as $k => $v) { $hash[$k] = $v; } $start_time = microtime(true); $value = $hash[$key]; $elapsed_time = microtime(true) - $start_time; echo "Hash table: $elapsed_time seconds\n";
Result:
Hashes are significantly faster than arrays and associative arrays for retrieving individual elements.
Find a specific element
// 数组(非有序) $start_time = microtime(true); $value = array_search($key, $array); $elapsed_time = microtime(true) - $start_time; echo "Indexed array: $elapsed_time seconds\n"; // 关联数组(有序) // 使用 array_flip 进行有序转换 $array = array_flip($array); $start_time = microtime(true); $value = array_search($key, $array); $elapsed_time = microtime(true) - $start_time; echo "Associative array: $elapsed_time seconds\n"; // 哈希表 $start_time = microtime(true); $value = isset($hash[$key]) ? $hash[$key] : null; $elapsed_time = microtime(true) - $start_time; echo "Hash table: $elapsed_time seconds\n";
Result:
For finding a specific element, the hash table again wins, while the array's Worst performance.
Add new elements
// 数组(非有序) $start_time = microtime(true); $array[] = $key; $elapsed_time = microtime(true) - $start_time; echo "Indexed array: $elapsed_time seconds\n"; // 关联数组(有序) $start_time = microtime(true); $array[$key] = $key; $elapsed_time = microtime(true) - $start_time; echo "Associative array: $elapsed_time seconds\n"; // 哈希表 $start_time = microtime(true); $hash[$key] = $key; $elapsed_time = microtime(true) - $start_time; echo "Hash table: $elapsed_time seconds\n";
Result:
For adding new elements, the performance of hash tables and arrays is close, Associative arrays are slightly slower.
Delete elements
// 数组(非有序) $start_time = microtime(true); unset($array[$key]); $elapsed_time = microtime(true) - $start_time; echo "Indexed array: $elapsed_time seconds\n"; // 关联数组(有序) $start_time = microtime(true); unset($array[$key]); $elapsed_time = microtime(true) - $start_time; echo "Associative array: $elapsed_time seconds\n"; // 哈希表 $start_time = microtime(true); unset($hash[$key]); $elapsed_time = microtime(true) - $start_time; echo "Hash table: $elapsed_time seconds\n";
Result:
For deleting elements, the performance of hash tables is significantly better than arrays and associative arrays better.
Conclusion
After performance comparison, we can draw the following conclusions:
- The hash table is very effective in retrieving a single element and finding a specific element. and excellent performance in removing elements.
- Arrays are fastest for adding new elements if ordered access is not required.
- Associative arrays are slower than hash tables when ordered access is required, but faster when adding new elements.
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