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run code in 200+ php & hhvm versions
Bugs & Features
<?php class CategoryTree { public $roots = []; public function addCategory($category, $parent) { if ($this->categoryExists($this->roots, $category)) { throw new InvalidArgumentException("Category: $category already exists."); } if ($parent === null) { $this->roots[$category] = []; return; } $node = &$this->findNode($parent, $this->roots); if(!isset($node)) { throw new InvalidArgumentException("Parent node: $parent not found."); } $node[$category] = []; } public function getChildren($parent) { $node = $this->findNode($parent, $this->roots); if(!isset($node)) { throw new InvalidArgumentException("Parent node: $parent not found."); } return array_keys($node); } protected function &findNode($node, &$root) { if (in_array($node, array_keys($root))) { return $root[$node]; } foreach ($root as $n) { return $this->findNode($node, $n); } } public function categoryExists($nodes, $category) { $exists = 'test'; if (in_array($category, array_keys($nodes))) { return true; } foreach($nodes as $key => $node) { $exists = $this->categoryExists($node, $category); } return $exists; } } // For testing purposes (do not submit uncommented): $c = new CategoryTree; $c->addCategory('A', null); $c->addCategory('B', 'A'); $c->addCategory('C', 'A'); echo implode(',', $c->getChildren('A')); echo "\n". $c->categoryExists($c->roots, 'D');
based on g0POD
Output for 7.0.0 - 7.2.0
Fatal error: Uncaught InvalidArgumentException: Category: A already exists. in /in/Rk0hp:9 Stack trace: #0 /in/Rk0hp(56): CategoryTree->addCategory('A', NULL) #1 {main} thrown in /in/Rk0hp on line 9
Process exited with code 255.
Output for 5.4.10 - 5.6.28
Fatal error: Uncaught exception 'InvalidArgumentException' with message 'Category: A already exists.' in /in/Rk0hp:9 Stack trace: #0 /in/Rk0hp(56): CategoryTree->addCategory('A', NULL) #1 {main} thrown in /in/Rk0hp on line 9
Process exited with code 255.
Output for 5.3.20 - 5.3.29
Parse error: syntax error, unexpected '[' in /in/Rk0hp on line 4
Process exited with code 255.