# 3v4l.org

run code in 200+ php & hhvm versions
```<?php class Node { public \$data = null; public \$parent = null; public \$left = null; public \$right = null; } #使用数组构造完全二叉树 function build_cbtree(\$a) { \$root = new Node(); \$root->data = \$a[0]; for (\$i = 1; \$i < count(\$a); \$i++) { \$node = new Node(); \$node->data = \$a[\$i]; insert_node(\$root, \$node); } return \$root; } #插入完全二叉树节点 function insert_node(\$root, \$inode) { #使用树的广度优先遍历顺序取出节点，直到找到第一个左右子节点没满的节点，将待插入节点插入节点左边或右边 \$queue = array(); array_unshift(\$queue, \$root); while (!empty(\$queue)) { \$cnode = array_pop(\$queue); if (\$cnode->left == null) { \$cnode->left = \$inode; \$inode->parent = \$cnode; return \$root; } else { array_unshift(\$queue, \$cnode->left); } if (\$cnode->right == null) { \$cnode->right = \$inode; \$inode->parent = \$cnode; return \$root; } else { array_unshift(\$queue, \$cnode->right); } } return \$root; } #树的广度优先遍历 function bf_traverse(\$root) { \$queue = array(); array_unshift(\$queue, \$root); while (!empty(\$queue)) { \$cnode = array_pop(\$queue); echo \$cnode->data . " "; if (\$cnode->left !== null) array_unshift(\$queue, \$cnode->left); if (\$cnode->right !== null) array_unshift(\$queue, \$cnode->right); } echo "<br>"; } \$a = array(9, 8, 7, 6, 8, 4, 3, 2, 1); \$root = build_cbtree(\$a); bf_traverse(\$root); #广度优先遍历 ?>```
Output for 5.0.0 - 7.2.0
9 8 7 6 8 4 3 2 1 <br>
Output for 4.4.2 - 4.4.9
Parse error: syntax error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or '}' in /in/ro1oV on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.4.1
Parse error: parse error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or '}' in /in/ro1oV on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error, expecting `T_OLD_FUNCTION' or `T_FUNCTION' or `T_VAR' or `'}'' in /in/ro1oV on line 3
Process exited with code 255.