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How Can I Build a Hierarchical Tree Structure in PHP from Parent-Child Relationships?
How Can I Build a Hierarchical Tree Structure in PHP from Parent-Child Relationships?
Dec 14, 2024 am 11:41 AM
Hierarchical Tree Structure Creation from Parent-Child Relationships
Constructing hierarchical tree structures from parent-child relationships is a common task in programming. To achieve this, a recursive approach can be employed, effectively organizing the data into nested units.
In PHP, converting a series of parent-child pairs into a hierarchical tree requires two key functions: parsing and printing. The parsing function systematically traverses the child-parent pairs to build a hierarchical data structure. Following this, the printing function converts this structure into a series of nested HTML unordered lists, with each list item representing a child.
As an example, consider the following parent-child pairs:
Child : Parent H : G F : G G : D E : D A : E B : C C : E D : NULL
To parse this data, we define the parseTree function:
function parseTree($tree, $root = null) {
$return = array();
foreach($tree as $child => $parent) {
if($parent == $root) {
unset($tree[$child]);
$return[] = array(
'name' => $child,
'children' => parseTree($tree, $child)
);
}
}
return empty($return) ? null : $return;
}
Next, we define the printTree function to convert the parsed hierarchy into HTML unordered lists:
function printTree($tree) {
if(!is_null($tree) && count($tree) > 0) {
echo '<ul>';
foreach($tree as $node) {
echo '<li>'.$node['name'];
printTree($node['children']);
echo '</li>';
}
echo '</ul>';
}
}
By combining these two functions, we can successfully convert child-parent pairs into hierarchical tree structures.
The above is the detailed content of How Can I Build a Hierarchical Tree Structure in PHP from Parent-Child Relationships?. For more information, please follow other related articles on the PHP Chinese website!
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