生成树型结构(比如省市区)

php中文网

发布时间：2016-05-25 18:02:51

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来源于php中文网

原创

<br><?<span style="color: #000000;">php
</span><span style="color: #008080;">header</span>("Content-type: text/html; charset=utf-8"<span style="color: #000000;">);

</span><span style="color: #0000ff;">function</span> generateTree(<span style="color: #800080;">$items</span><span style="color: #000000;">)
{
    </span><span style="color: #800080;">$tree</span> = <span style="color: #0000ff;">array</span><span style="color: #000000;">();
    </span><span style="color: #0000ff;">foreach</span>(<span style="color: #800080;">$items</span> <span style="color: #0000ff;">as</span> <span style="color: #800080;">$item</span><span style="color: #000000;">){
        </span><span style="color: #0000ff;">if</span>(<span style="color: #0000ff;">isset</span>(<span style="color: #800080;">$items</span>[<span style="color: #800080;">$item</span>['pid'<span style="color: #000000;">]])){
            </span><span style="color: #800080;">$items</span>[<span style="color: #800080;">$item</span>['pid']]['son'][] = &<span style="color: #800080;">$items</span>[<span style="color: #800080;">$item</span>['id'<span style="color: #000000;">]];
        }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
            </span><span style="color: #800080;">$tree</span>[] = &<span style="color: #800080;">$items</span>[<span style="color: #800080;">$item</span>['id'<span style="color: #000000;">]];
        }
    }
    </span><span style="color: #0000ff;">return</span> <span style="color: #800080;">$tree</span><span style="color: #000000;">;
}<br>//需要注意的一点，数组的key值必须与id值保持一致
</span><span style="color: #800080;">$items</span> = <span style="color: #0000ff;">array</span><span style="color: #000000;">(
    </span>1 => <span style="color: #0000ff;">array</span>('id' => 1, 'pid' => 0, 'name' => '安徽省'),
    2 => <span style="color: #0000ff;">array</span>('id' => 2, 'pid' => 0, 'name' => '浙江省'),
    3 => <span style="color: #0000ff;">array</span>('id' => 3, 'pid' => 1, 'name' => '合肥市'),
    4 => <span style="color: #0000ff;">array</span>('id' => 4, 'pid' => 3, 'name' => '长丰县'),
    5 => <span style="color: #0000ff;">array</span>('id' => 5, 'pid' => 1, 'name' => '安庆市'),<span style="color: #000000;">
);
</span><span style="color: #0000ff;">echo</span> "<pre class="brush:php;toolbar:false;">"<span style="color: #000000;">;
</span><span style="color: #008080;">print_r</span>(generateTree(<span style="color: #800080;">$items</span>));

上面方法的优化：

<?<span style="color: #000000;">php
</span><span style="color: #008080;">header</span>("Content-type: text/html; charset=utf-8"<span style="color: #000000;">);

</span><span style="color: #0000ff;">function</span> generateTree(<span style="color: #800080;">$items</span><span style="color: #000000;">)
{
    </span><span style="color: #0000ff;">foreach</span>(<span style="color: #800080;">$items</span> <span style="color: #0000ff;">as</span> <span style="color: #800080;">$item</span><span style="color: #000000;">)
        </span><span style="color: #800080;">$items</span>[<span style="color: #800080;">$item</span>['pid']]['son'][<span style="color: #800080;">$item</span>['id']] = &<span style="color: #800080;">$items</span>[<span style="color: #800080;">$item</span>['id'<span style="color: #000000;">]];
    </span><span style="color: #0000ff;">return</span> <span style="color: #0000ff;">isset</span>(<span style="color: #800080;">$items</span>[0]['son']) ? <span style="color: #800080;">$items</span>[0]['son'] : <span style="color: #0000ff;">array</span><span style="color: #000000;">();
}

</span><span style="color: #008000;">//</span><span style="color: #008000;">需要注意的一点，数组的key值必须与id保持一致</span>
<span style="color: #800080;">$items</span> = <span style="color: #0000ff;">array</span><span style="color: #000000;">(
    </span>1 => <span style="color: #0000ff;">array</span>('id' => 1, 'pid' => 0, 'name' => '安徽省'),
    2 => <span style="color: #0000ff;">array</span>('id' => 2, 'pid' => 0, 'name' => '浙江省'),
    3 => <span style="color: #0000ff;">array</span>('id' => 3, 'pid' => 1, 'name' => '合肥市'),
    4 => <span style="color: #0000ff;">array</span>('id' => 4, 'pid' => 3, 'name' => '长丰县'),
    5 => <span style="color: #0000ff;">array</span>('id' => 5, 'pid' => 1, 'name' => '安庆市'),<span style="color: #000000;">
);
</span><span style="color: #0000ff;">echo</span> "<pre class="brush:php;toolbar:false;">"<span style="color: #000000;">;
</span><span style="color: #008080;">print_r</span>(generateTree(<span style="color: #800080;">$items</span>));

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结果：