arsort與ksort聯合使用，實現多條件排序的具體方法有哪些？

gitbox 2025-08-12

在PHP中，數組排序是數據處理中的常見操作，尤其在面對多維數組或者需要多條件排序的場景時，選擇合適的排序函數尤為重要。 arsort()和ksort()是兩個經常被聯合使用的函數，通過它們的組合，可以實現對數組的值和鍵進行有序管理。本文將結合具體代碼示例，詳細講解這兩個函數如何联合使用以實現多條件排序。

一、arsort與ksort的基礎功能

arsort() ：對數組進行降序排序，保留鍵名，按“值”排序。
ksort() ：對數組按“鍵”進行升序排序，保留鍵值。

雖然這兩個函數本質上是分別作用於“值”和“鍵”的排序，但在某些場景中，可以通過聯合使用它們，實現更靈活的多條件排序邏輯。

二、多條件排序需求舉例

假設有如下一個數組，表示多個用戶的得分記錄：

 <span><span><span class="hljs-variable">$users</span></span><span> = [
    </span><span><span class="hljs-string">'user3'</span></span><span> =&gt; [</span><span><span class="hljs-string">'score'</span></span><span> =&gt; </span><span><span class="hljs-number">85</span></span><span>, </span><span><span class="hljs-string">'time'</span></span><span> =&gt; </span><span><span class="hljs-number">120</span></span><span>],
    </span><span><span class="hljs-string">'user1'</span></span><span> =&gt; [</span><span><span class="hljs-string">'score'</span></span><span> =&gt; </span><span><span class="hljs-number">92</span></span><span>, </span><span><span class="hljs-string">'time'</span></span><span> =&gt; </span><span><span class="hljs-number">110</span></span><span>],
    </span><span><span class="hljs-string">'user2'</span></span><span> =&gt; [</span><span><span class="hljs-string">'score'</span></span><span> =&gt; </span><span><span class="hljs-number">85</span></span><span>, </span><span><span class="hljs-string">'time'</span></span><span> =&gt; </span><span><span class="hljs-number">100</span></span><span>],
    </span><span><span class="hljs-string">'user4'</span></span><span> =&gt; [</span><span><span class="hljs-string">'score'</span></span><span> =&gt; </span><span><span class="hljs-number">92</span></span><span>, </span><span><span class="hljs-string">'time'</span></span><span> =&gt; </span><span><span class="hljs-number">130</span></span><span>],
];
</span></span>

現在的需求是：

首先按得分（score）降序排序；
若得分相同，則按完成時間（time）升序排序；
若得分和時間都相同，再按用戶名（鍵名）升序排序。

三、實現方法

步驟1：自定義排序邏輯

為了實現複雜排序，可以使用uasort()結合自定義函數：

 <span><span><span class="hljs-title function_ invoke__">uasort</span></span><span>(</span><span><span class="hljs-variable">$users</span></span><span>, function(</span><span><span class="hljs-variable">$a</span></span><span>, </span><span><span class="hljs-variable">$b</span></span><span>) {
    </span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-variable">$a</span></span><span>[</span><span><span class="hljs-string">'score'</span></span><span>] == </span><span><span class="hljs-variable">$b</span></span><span>[</span><span><span class="hljs-string">'score'</span></span><span>]) {
        </span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-variable">$a</span></span><span>[</span><span><span class="hljs-string">'time'</span></span><span>] == </span><span><span class="hljs-variable">$b</span></span><span>[</span><span><span class="hljs-string">'time'</span></span><span>]) {
            </span><span><span class="hljs-keyword">return</span></span><span> </span><span><span class="hljs-number">0</span></span><span>; </span><span><span class="hljs-comment">// 留待後續使用ksort處理鍵名排序</span></span><span>
        }
        </span><span><span class="hljs-keyword">return</span></span><span> (</span><span><span class="hljs-variable">$a</span></span><span>[</span><span><span class="hljs-string">'time'</span></span><span>] &lt; </span><span><span class="hljs-variable">$b</span></span><span>[</span><span><span class="hljs-string">'time'</span></span><span>]) ? -</span><span><span class="hljs-number">1</span></span><span> : </span><span><span class="hljs-number">1</span></span><span>; </span><span><span class="hljs-comment">// 時間升序</span></span><span>
    }
    </span><span><span class="hljs-keyword">return</span></span><span> (</span><span><span class="hljs-variable">$a</span></span><span>[</span><span><span class="hljs-string">'score'</span></span><span>] &gt; </span><span><span class="hljs-variable">$b</span></span><span>[</span><span><span class="hljs-string">'score'</span></span><span>]) ? -</span><span><span class="hljs-number">1</span></span><span> : </span><span><span class="hljs-number">1</span></span><span>; </span><span><span class="hljs-comment">// 得分降序</span></span><span>
});
</span></span>

步驟2：處理鍵名相同排序

由於uasort()不影響鍵名的順序，我們可以再用ksort()來對鍵名進行排序，但這一步只有在值相同時才有意義。可以利用中間轉換結構：

 <span><span><span class="hljs-comment">// 將排序後的數組按鍵重新分組</span></span><span>
</span><span><span class="hljs-variable">$temp</span></span><span> = [];
</span><span><span class="hljs-keyword">foreach</span></span><span> (</span><span><span class="hljs-variable">$users</span></span><span> </span><span><span class="hljs-keyword">as</span></span><span> </span><span><span class="hljs-variable">$key</span></span><span> =&gt; </span><span><span class="hljs-variable">$value</span></span><span>) {
    </span><span><span class="hljs-variable">$groupKey</span></span><span> = </span><span><span class="hljs-variable">$value</span></span><span>[</span><span><span class="hljs-string">'score'</span></span><span>] . </span><span><span class="hljs-string">'-'</span></span><span> . </span><span><span class="hljs-variable">$value</span></span><span>[</span><span><span class="hljs-string">'time'</span></span><span>];
    </span><span><span class="hljs-variable">$temp</span></span><span>[</span><span><span class="hljs-variable">$groupKey</span></span><span>][</span><span><span class="hljs-variable">$key</span></span><span>] = </span><span><span class="hljs-variable">$value</span></span><span>;
}

</span><span><span class="hljs-comment">// 對每組鍵名排序</span></span><span>
</span><span><span class="hljs-keyword">foreach</span></span><span> (</span><span><span class="hljs-variable">$temp</span></span><span> </span><span><span class="hljs-keyword">as</span></span><span> &amp;</span><span><span class="hljs-variable">$group</span></span><span>) {
    </span><span><span class="hljs-title function_ invoke__">ksort</span></span><span>(</span><span><span class="hljs-variable">$group</span></span><span>); </span><span><span class="hljs-comment">// 鍵名升序</span></span><span>
}

</span><span><span class="hljs-comment">// 合併成最終結果</span></span><span>
</span><span><span class="hljs-variable">$final</span></span><span> = [];
</span><span><span class="hljs-keyword">foreach</span></span><span> (</span><span><span class="hljs-variable">$temp</span></span><span> </span><span><span class="hljs-keyword">as</span></span><span> </span><span><span class="hljs-variable">$group</span></span><span>) {
    </span><span><span class="hljs-keyword">foreach</span></span><span> (</span><span><span class="hljs-variable">$group</span></span><span> </span><span><span class="hljs-keyword">as</span></span><span> </span><span><span class="hljs-variable">$k</span></span><span> =&gt; </span><span><span class="hljs-variable">$v</span></span><span>) {
        </span><span><span class="hljs-variable">$final</span></span><span>[</span><span><span class="hljs-variable">$k</span></span><span>] = </span><span><span class="hljs-variable">$v</span></span><span>;
    }
}
</span></span>

此時， $final就是我們期望的，按照score 降序、time 升序、鍵名升序排列的結果。

四、簡化版實現（二維排序+ 鍵名）

在實際項目中，也可以將數據拍平、引入排序權重，結合array_multisort()來操作，但這種方法對保持鍵名不太友好。聯合使用arsort和ksort的方式，則可以保留關聯數組的完整結構和鍵名。

五、小結

arsort()和ksort()本身並不能直接支持多條件排序，但通過分組處理與多步排序邏輯，結合uasort()等函數，可以靈活地實現類似SQL 中的ORDER BY col1 DESC, col2 ASC的效果。掌握這些排序技巧，有助於開發者在處理複雜數組數據時更加得心應手。