Memory efficiency optimization tips for PHP array intersection and union

PHP array intersection and union operations in large arrays can improve performance through optimization techniques. Techniques include: use the in_array() function to quickly search when intersecting; use the array_intersect() function to compare arrays of similar sizes; use the array_unique() function to remove duplicate elements when union; use operators to get duplicate elements Union.

Memory efficiency optimization tips for PHP array intersection and union

PHP array intersection and union operations are often used in daily development used. However, for large arrays, these operations can be very time-consuming and consume large amounts of memory. In order to optimize performance, we can use the following techniques:

Intersection

• ##Use thein_array()function:If the number of elements in array A is much smaller than array B, we can use thein_array()function to search for each element in array A in array B.

function getIntersect($arrA, $arrB) { $result = []; foreach ($arrA as $value) { if (in_array($value, $arrB)) { $result[] = $value; } } return $result; }

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• Use thearray_intersect()function:If the two arrays are of similar size, you can use thearray_intersect()function .

function getIntersect($arrA, $arrB) { return array_intersect($arrA, $arrB); }

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Union

• Use thearray_unique()function:If you need to return a non- For repeated unions, you can use thearray_unique()function to merge two arrays and remove duplicate elements.

function getUnion($arrA, $arrB) { return array_unique(array_merge($arrA, $arrB)); }

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• Useoperator:If you do not need to return a unique union, you can use theoperator and two arrays.

function getUnion($arrA, $arrB) { return $arrA + $arrB; }

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Practical case

$arrA = range(1, 100000); $arrB = range(50001, 150000);

// 交集（使用 in_array() 函数） $intersect = getIntersect($arrA, $arrB); // 并集（使用 array_unique() 函数） $union = getUnion($arrA, $arrB); printf("交集大小：%d\n", count($intersect)); printf("并集大小：%d\n", count($union));

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