有没有办法找出PHP数组的“深度”？

Question

PHP数组可以为其元素包含数组。这些数组可以具有数组，依此类推。有没有办法找出PHP数组中存在的最大嵌套？一个示例是一个函数，如果初始数组不具有数组作为元素，则返回1；如果至少一个元素是数组，则返回2，依此类推。

Answer 1

应该这样做：<?phpfunction array_depth(array $array) {&nbsp; &nbsp; $max_depth = 1;&nbsp; &nbsp; foreach ($array as $value) {&nbsp; &nbsp; &nbsp; &nbsp; if (is_array($value)) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; $depth = array_depth($value) + 1;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if ($depth > $max_depth) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; $max_depth = $depth;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; return $max_depth;}?>编辑：非常快速地测试了它，它似乎可以工作。

Answer 2

这是避免Kent Fredric指出的问题的另一种选择。它为print_r（）提供了检查无限递归的功能（它做得很好），并使用输出中的缩进来查找数组的深度。function array_depth($array) {&nbsp; &nbsp; $max_indentation = 1;&nbsp; &nbsp; $array_str = print_r($array, true);&nbsp; &nbsp; $lines = explode("\n", $array_str);&nbsp; &nbsp; foreach ($lines as $line) {&nbsp; &nbsp; &nbsp; &nbsp; $indentation = (strlen($line) - strlen(ltrim($line))) / 4;&nbsp; &nbsp; &nbsp; &nbsp; if ($indentation > $max_indentation) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; $max_indentation = $indentation;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; return ceil(($max_indentation - 1) / 2) + 1;}