How to use the urlencode function to encode special characters in PHP

In PHP, we often need to encode special characters in the URL in order to pass parameters correctly. At this time, you can use the urlencode function.

The urlencode function is to encode the special characters in the string so that they can be passed in the URL. These special characters include: alphanumeric characters, punctuation marks, protocol characters, some reserved characters, etc.

The following is the basic syntax of the urlencode function:

urlencode(string $str) : string

Among them, $str is the string to be encoded.

The following is an example showing how to use the urlencode function to encode a string:

$str = "hello world!";
echo "Original String: ".$str."
";
echo "Encoded string: ".urlencode($str)."
";
?>

Output result:

Original string: hello world!
Encoded string: hello world!

As can be seen from the above example, the urlencode function will convert spaces into The plus sign, and the exclamation mark became !.

In addition to common punctuation and alphanumeric characters, the urlencode function can also handle some special characters, such as:

• Space ( ) ->
• Because in the URL, the space is considered a special character (delimiter), so it needs to be encoded.
• Punctuation characters (for example: !, #, $, %, etc.) -> %HEXCODE
• Protocol characters (for example:, /, ?, #, etc.) -> %HEXCODE
• Some reserved characters (for example: &, =, etc.) -> %HEXCODE

Therefore, using the urlencode function can ensure that parameters are passed correctly in the URL without An error occurs due to the presence of special characters.

The last thing to note is that the urlencode function will only encode the specified characters and does not do anything with other characters. Therefore, when using the urlencode function to encode URLs, you should follow the corresponding rules and do not add special characters at will.

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