HTML entities and HTML special characters

htmlentites_and_htmlspecialchars_charset.php

<?php

error_reporting(E_ALL);

$charsets = array(
    "ISO-8859-1" => "Western European, Latin-1. ",
    "ISO-8859-5" => "Little used cyrillic charset (Latin/Cyrillic). ",
    "ISO-8859-15" => "Western European, Latin-9. Adds the Euro sign, French and Finnish letters missing in Latin-1 (ISO-8859-1). ",
    "UTF-8" => "ASCII compatible multi-byte 8-bit Unicode. ",
    "cp866" => "DOS-specific Cyrillic charset. ",
    "cp1251" => "Windows-specific Cyrillic charset. ",
    "cp1252" => "Windows specific charset for Western European. ",
    "KOI8-R" => "Russian. ",
    "BIG5" => "Traditional Chinese, mainly used in Taiwan. ",
    "GB2312" => "Simplified Chinese, national standard character set. ",
    "BIG5-HKSCS" => "Big5 with Hong Kong extensions, Traditional Chinese. ",
    "Shift_JIS" => "Japanese Shift_JIS",
    "EUC-JP" => "Japanese EUC-JP",
    "MacRoman" => "Charset that was used by Mac OS. ",
);

header('content-type: text/plain; charset=ISO-8859-15');

foreach ($charsets as $charset => $description) {
    $htmlTransitionTableHTMLEntities = get_html_translation_table(HTML_ENTITIES, ENT_COMPAT | ENT_QUOTES, $charset);
    $listTableHTMLEntities = implode(",", array_flip($htmlTransitionTableHTMLEntities));

    echo "\n========================================================================\n";
    echo $description;
    echo "\n========================================================================\n";

    print_r($listTableHTMLEntities);
    echo "\n========================================================================\n";

//    Convert all applicable characters to HTML entities
    $htmlentitiesResult = htmlentities($listTableHTMLEntities, ENT_QUOTES, $charset);
    echo $htmlentitiesResult;
    echo "\n========================================================================\n";
    
//    Decode it again
    echo html_entity_decode($htmlentitiesResult, ENT_QUOTES, $charset);
    echo "\n========================================================================\n";
    
//    Convert special characters to HTML entities
//    The translations performed are:
//
//    ◦'&' (ampersand) becomes '&amp;'
//    ◦'"' (double quote) becomes '&quot;' when ENT_NOQUOTES is not set.
//    ◦"'" (single quote) becomes '&#039;' (or &apos;
//    ) only when ENT_QUOTES is set.
//    ◦'<' (less than) becomes '&lt;'
//    ◦'>' (greater than) becomes '&gt;' 
    $htmlspecialcharsResult = htmlspecialchars($listTableHTMLEntities, ENT_QUOTES, $charset);
    echo $htmlspecialcharsResult;
    echo "\n========================================================================\n";

//    Decode it again
    echo htmlspecialchars_decode($htmlspecialcharsResult, ENT_QUOTES);
    echo "\n========================================================================\n";
}

exit;
?>