Accelerate PHP function performance: a collection of optimization tips

PHP function performance optimization method: cache results: avoid repeated calculations and improve performance. Reduce unnecessary allocations: reuse variables or use read-only variables to avoid memory allocation affecting performance. Use built-in functions: Use PHP's built-in efficient functions to improve code execution efficiency. Optimize array traversal: use efficient iterators or foreach loops to reduce performance bottlenecks. Reduce the number of function calls: Reduce unnecessary function calls and consider performing multiple operations at once or using anonymous functions.

Accelerate PHP function performance: a collection of optimization tips

Performance optimization of PHP functions is crucial to improving application speed. This article will provide comprehensive tips to help you optimize function performance, with practical examples.

Caching results

For frequently called functions, caching results can avoid repeated calculations, thereby significantly improving performance.

$cache = array();  // 全局缓存数组

function fibonacci($n) {
    global $cache;

    if (isset($cache[$n])) {
        return $cache[$n];
    }

    if ($n <= 1) {
        $cache[$n] = $n;
    } else {
        $cache[$n] = fibonacci($n - 1) + fibonacci($n - 2);
    }

    return $cache[$n];
}

Avoid unnecessary allocation

Allocating memory inside a function will affect performance. Try to reuse existing variables or use read-only variables.

function sum($arr) {
    $sum = 0;  // 复用变量避免分配

    foreach ($arr as $value) {
        $sum += $value;
    }

    return $sum;
}

Use built-in functions

PHP has many built-in efficient functions. Try to use them instead of implementing it yourself.

// 使用内置的 `array_merge`，而不是自己实现
$merged = array_merge($arr1, $arr2);

Optimizing array traversal

Array traversal is a common performance bottleneck. Use efficient iterators or foreach loops.

// 使用 `array_map` 同时遍历多个数组
$mapped = array_map(function($v1, $v2) { return $v1 + $v2; }, $arr1, $arr2);

// 使用 foreach 循环避免重新索引
foreach ($arr as $key => &$value) {
    // ...
}

Reduce the number of function calls

Reduce unnecessary function calls as much as possible. Consider performing multiple operations at once or using anonymous functions.

// 减少 `count()` 调用次数
$count = count($arr);

// 使用匿名函数一次性处理多个操作
array_walk($arr, function(&$v) { $v *= 2; });

Practical case

Case 1: Optimizing string splicing

Use the StringBuilder class instead of splicing strings one by one, which greatly improves the efficiency of string splicing. Improved speed.

class StringBuilder {
    private $data = "";

    public function append($str) {
        $this->data .= $str;
    }

    public function toString() {
        return $this->data;
    }
}

// 实战
$stringBuilder = new StringBuilder();
for ($i = 0; $i < 10000; $i++) {
    $stringBuilder->append("Hello world!");
}
$str = $stringBuilder->toString();

Case 2: Optimizing array sorting

Optimize array sorting by pre-allocating space and using efficient sorting algorithms (such as quick sort).

// 预先分配空间
$arr = range(0, 10000);
shuffle($arr);  // 打乱数组

// 快排排序
function quickSort($arr, $low, $high) {
    if ($low < $high) {
        $partitionIndex = partition($arr, $low, $high);
        quickSort($arr, $low, $partitionIndex - 1);
        quickSort($arr, $partitionIndex + 1, $high);
    }
}

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