如何結合http_build_query 和$_GET 數組來拼接URL 參數，實用技巧分享

M66 2025-07-08

在PHP 中，處理URL 參數是一項常見任務，尤其是當我們需要根據不同的需求動態生成和修改URL 時。 http_build_query函數和$_GET數組是兩種常用的工具，它們幫助我們方便地構建URL 參數。今天，我們將討論如何結合這兩者，使用更簡單的方式來拼接和操作URL 參數。

1. http_build_query函數介紹

http_build_query是PHP 內置的一個函數，它接受一個關聯數組或者多維數組，並將其轉換為URL 查詢字符串。該函數不僅能幫助你快速生成查詢參數，還會自動進行URL 編碼，確保查詢字符串符合URL 標準。

函數語法：

 <span><span><span class="hljs-keyword">string</span></span><span> </span><span><span class="hljs-title function_ invoke__">http_build_query</span></span><span> ( </span><span><span class="hljs-keyword">array</span></span><span> </span><span><span class="hljs-variable">$query_data</span></span><span> [, </span><span><span class="hljs-keyword">string</span></span><span> </span><span><span class="hljs-variable">$numeric_prefix</span></span><span> = </span><span><span class="hljs-string">""</span></span><span> [, </span><span><span class="hljs-keyword">string</span></span><span> </span><span><span class="hljs-variable">$arg_separator</span></span><span> = </span><span><span class="hljs-string">"&amp;"</span></span><span> ]] )
</span></span>

$query_data ：一個關聯數組，包含鍵值對，將會被轉換為查詢字符串。
$numeric_prefix ：如果數組中的鍵是數字，你可以選擇在這些鍵前加上前綴。
$arg_separator ：指定多個參數之間的分隔符，默認為& 。

2. 使用http_build_query拼接URL 參數

假設我們有一個包含多個參數的數組，如何將這些參數拼接成一個完整的URL 查詢字符串呢？這時， http_build_query就能幫上忙了。

示例：

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-variable">$params</span></span><span> = [
    </span><span><span class="hljs-string">'search'</span></span><span> =&gt; </span><span><span class="hljs-string">'PHP'</span></span><span>,
    </span><span><span class="hljs-string">'page'</span></span><span> =&gt; </span><span><span class="hljs-number">2</span></span><span>,
    </span><span><span class="hljs-string">'sort'</span></span><span> =&gt; </span><span><span class="hljs-string">'asc'</span></span><span>,
    </span><span><span class="hljs-string">'category'</span></span><span> =&gt; </span><span><span class="hljs-string">'programming'</span></span><span>
];

</span><span><span class="hljs-comment">// 拼接 URL 參數</span></span><span>
</span><span><span class="hljs-variable">$queryString</span></span><span> = </span><span><span class="hljs-title function_ invoke__">http_build_query</span></span><span>(</span><span><span class="hljs-variable">$params</span></span><span>);

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$queryString</span></span><span>; 
</span><span><span class="hljs-comment">// 輸出: search=PHP&amp;page=2&amp;sort=asc&amp;category=programming</span></span><span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

通過這個方法，我們就可以輕鬆地生成一個標準的查詢字符串。

3. 將查詢字符串添加到基礎URL

有時候我們需要將拼接好的查詢字符串添加到一個已有的基礎URL 中。這可以通過簡單地將查詢字符串追加到基礎URL 後實現。

示例：

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-variable">$baseURL</span></span><span> = </span><span><span class="hljs-string">"https://example.com/products?"</span></span><span>;
</span><span><span class="hljs-variable">$params</span></span><span> = [
    </span><span><span class="hljs-string">'search'</span></span><span> =&gt; </span><span><span class="hljs-string">'PHP'</span></span><span>,
    </span><span><span class="hljs-string">'page'</span></span><span> =&gt; </span><span><span class="hljs-number">2</span></span><span>,
    </span><span><span class="hljs-string">'sort'</span></span><span> =&gt; </span><span><span class="hljs-string">'asc'</span></span><span>,
    </span><span><span class="hljs-string">'category'</span></span><span> =&gt; </span><span><span class="hljs-string">'programming'</span></span><span>
];

</span><span><span class="hljs-comment">// 拼接查詢字符串</span></span><span>
</span><span><span class="hljs-variable">$queryString</span></span><span> = </span><span><span class="hljs-title function_ invoke__">http_build_query</span></span><span>(</span><span><span class="hljs-variable">$params</span></span><span>);

</span><span><span class="hljs-comment">// 完整的 URL</span></span><span>
</span><span><span class="hljs-variable">$fullURL</span></span><span> = </span><span><span class="hljs-variable">$baseURL</span></span><span> . </span><span><span class="hljs-variable">$queryString</span></span><span>;

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$fullURL</span></span><span>;
</span><span><span class="hljs-comment">// 輸出: https://example.com/products?search=PHP&amp;page=2&amp;sort=asc&amp;category=programming</span></span><span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

4. 使用$_GET數組動態處理URL 參數

$_GET是PHP 超全局數組，用於獲取URL 中查詢字符串的值。當用戶訪問帶有查詢參數的URL 時， $_GET會自動將這些參數解析成數組。例如，訪問https://example.com/?search=PHP&page=2時，可以通過$_GET['search']獲取到參數search的值。

示例：

假設我們希望獲取當前URL 中的所有參數，並根據需要進行修改或添加新的參數。

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 假設當前 URL 為: https://example.com/?search=PHP&amp;page=2</span></span><span>
</span><span><span class="hljs-comment">// $_GET 数组会自动包含查询參數</span></span><span>
</span><span><span class="hljs-variable">$currentParams</span></span><span> = </span><span><span class="hljs-variable">$_GET</span></span><span>;

</span><span><span class="hljs-comment">// 添加新的參數</span></span><span>
</span><span><span class="hljs-variable">$currentParams</span></span><span>[</span><span><span class="hljs-string">'sort'</span></span><span>] = </span><span><span class="hljs-string">'desc'</span></span><span>;

</span><span><span class="hljs-comment">// 使用 http_build_query 拼接更新後的查詢字符串</span></span><span>
</span><span><span class="hljs-variable">$newQueryString</span></span><span> = </span><span><span class="hljs-title function_ invoke__">http_build_query</span></span><span>(</span><span><span class="hljs-variable">$currentParams</span></span><span>);

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$newQueryString</span></span><span>;
</span><span><span class="hljs-comment">// 輸出: search=PHP&amp;page=2&amp;sort=desc</span></span><span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

5. 修改某個URL 參數

有時我們只想修改URL 中的某個參數，而不是重新構建整個查詢字符串。可以通過修改$_GET數組中的相應鍵，然後再使用http_build_query來生成新的查詢字符串。

示例：

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 假設當前 URL 為: https://example.com/?search=PHP&amp;page=2</span></span><span>
</span><span><span class="hljs-comment">// 获取当前參數</span></span><span>
</span><span><span class="hljs-variable">$currentParams</span></span><span> = </span><span><span class="hljs-variable">$_GET</span></span><span>;

</span><span><span class="hljs-comment">// 修改某个參數</span></span><span>
</span><span><span class="hljs-variable">$currentParams</span></span><span>[</span><span><span class="hljs-string">'page'</span></span><span>] = </span><span><span class="hljs-number">3</span></span><span>;

</span><span><span class="hljs-comment">// 使用 http_build_query 生成新的查詢字符串</span></span><span>
</span><span><span class="hljs-variable">$newQueryString</span></span><span> = </span><span><span class="hljs-title function_ invoke__">http_build_query</span></span><span>(</span><span><span class="hljs-variable">$currentParams</span></span><span>);

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$newQueryString</span></span><span>;
</span><span><span class="hljs-comment">// 輸出: search=PHP&amp;page=3</span></span><span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

6. 高級用法：處理多維數組

http_build_query也支持處理多維數組。如果你有一個嵌套數組，函數會自動將其展平，並生成符合標準的查詢字符串。

示例：

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-variable">$params</span></span><span> = [
    </span><span><span class="hljs-string">'search'</span></span><span> =&gt; </span><span><span class="hljs-string">'PHP'</span></span><span>,
    </span><span><span class="hljs-string">'filters'</span></span><span> =&gt; [
        </span><span><span class="hljs-string">'category'</span></span><span> =&gt; </span><span><span class="hljs-string">'programming'</span></span><span>,
        </span><span><span class="hljs-string">'price'</span></span><span> =&gt; </span><span><span class="hljs-string">'low'</span></span><span>
    ]
];

</span><span><span class="hljs-comment">// 使用 http_build_query 拼接多維數組</span></span><span>
</span><span><span class="hljs-variable">$queryString</span></span><span> = </span><span><span class="hljs-title function_ invoke__">http_build_query</span></span><span>(</span><span><span class="hljs-variable">$params</span></span><span>);

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$queryString</span></span><span>;
</span><span><span class="hljs-comment">// 輸出: search=PHP&amp;filters%5Bcategory%5D=programming&amp;filters%5Bprice%5D=low</span></span><span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

在這個例子中， http_build_query自動處理了嵌套的數組，並生成了符合URL 查詢字符串格式的結果。

7. 總結

http_build_query和$_GET數組是PHP 中非常實用的工具，幫助我們簡化了URL 參數的處理過程。通過合理運用這些工具，我們可以高效地拼接URL 參數、修改現有參數，甚至處理複雜的多維數組。掌握這些技巧，將讓你在開發過程中事半功倍。

http_build_query