Generate tree structure (such as provinces and cities), tree structure provinces and cities_PHP tutorial

Generate tree structure (such as provinces and cities), tree structure provinces and cities

<br /><?<span>php
</span><span>header</span>("Content-type: text/html; charset=utf-8"<span>);

</span><span>function</span> generateTree(<span>$items</span><span>)
{
    </span><span>$tree</span> = <span>array</span><span>();
    </span><span>foreach</span>(<span>$items</span> <span>as</span> <span>$item</span><span>){
        </span><span>if</span>(<span>isset</span>(<span>$items</span>[<span>$item</span>['pid'<span>]])){
            </span><span>$items</span>[<span>$item</span>['pid']]['son'][] = &<span>$items</span>[<span>$item</span>['id'<span>]];
        }</span><span>else</span><span>{
            </span><span>$tree</span>[] = &<span>$items</span>[<span>$item</span>['id'<span>]];
        }
    }
    </span><span>return</span> <span>$tree</span><span>;
}<br />//需要注意的一点，数组的key值必须与id值保持一致
</span><span>$items</span> = <span>array</span><span>(
    </span>1 => <span>array</span>('id' => 1, 'pid' => 0, 'name' => '安徽省'),
    2 => <span>array</span>('id' => 2, 'pid' => 0, 'name' => '浙江省'),
    3 => <span>array</span>('id' => 3, 'pid' => 1, 'name' => '合肥市'),
    4 => <span>array</span>('id' => 4, 'pid' => 3, 'name' => '长丰县'),
    5 => <span>array</span>('id' => 5, 'pid' => 1, 'name' => '安庆市'),<span>
);
</span><span>echo</span> "<pre class="brush:php;toolbar:false">"<span>;
</span><span>print_r</span>(generateTree(<span>$items</span>));

Optimization of the above method:

php header("Content-type: text/html; charset=utf-8"); function generateTree($items) { foreach($items as $item) $items[$item['pid']]['son'][$item['id']] = &$items[$item['id']]; return isset($items[0]['son']) ? $items[0]['son '] : array(); } //One thing to note is that the key value of the array must be consistent with the id $items = array( 1 => array('id' => 1, 'pid' => 0, 'name' => 'Anhui Province'), 2 => array('id' => 2, 'pid' => 0, 'name' => 'Zhejiang Province'), 3 => array('id' => 3, 'pid' => 1, 'name' => 'Hefei City'), 4 => array('id' => 4, 'pid' => 3, 'name' => 'Changfeng County'), 5 => array('id' => 5, 'pid' => 1, 'name' => 'Anqing City'), ); echo "

"<span>;
</span><span>print_r</span>(generateTree(<span>$items</span>));

View Code

Result:

http://www.bkjia.com/PHPjc/1128373.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/1128373.htmlTechArticleGenerate a tree structure (such as provinces and cities), tree structure provinces and cities? php header ("Content- type: text/html; charset=utf-8" ); function generateTree( $items ){ $tree = array (); foreach ( $...