How to Preserve the Plus Sign ( ) in a Query String?

How to keep the plus sign ( ) in the query string

In web development, query strings are crucial for passing parameters and values ​​to server-side scripts. However, special characters like " " can cause challenges when included in query strings.

Question:

How can I include " " in a query string without it disappearing due to its specific meaning in URL semantics?

Answer:

" " characters are interpreted as spaces in the query string. To preserve the literal " ", its URL needs to be encoded as "+".

Explanation:

URL encoding replaces special characters with their hexadecimal equivalents starting with "%". For " ", the URL encoding form is "+". When server-side scripts process query strings, they typically URL-decode the parameters, converting the "+" back to " ".

Example:

Consider the following query string:

• https://www.php.cn/link/eb352bcf0192b4f307d42f4033208256
• https://www.php.cn/link/c7f1734f2e7b3ea403e447de4a566ed2

The first query string will be decoded as "foo bar", while the second query string will retain the " " character.

JavaScript encoding:

If you are dynamically generating query strings in JavaScript, you can use the encodeURIComponent() function to encode parameters before appending them to the URL:

<code class="language-javascript">var encodedURL = "http://example.com/foo.php?var=" + encodeURIComponent(param);</code>

Remember that this encoding process is only required if you want to preserve the literal " ". If you intend for " " to be interpreted as a space, URL encoding is not required.

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