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In PHP, string encoding conversion and cleanup are very common operations. When dealing with text in different encoding formats—especially in cross-platform applications or when working with external data sources—maintaining character accuracy and consistency can be a challenge. convert_cyr_string and str_replace are both very useful tools in PHP, and today we’ll explore how they can be used together to achieve encoding cleanup and text normalization.
convert_cyr_string is a PHP function designed for converting Cyrillic character encodings. Cyrillic is an alphabet system used by many Eastern European languages. If you’re working with text in Russian or other languages that use Cyrillic, convert_cyr_string can be particularly helpful.
The function prototype is:
<span><span><span class="hljs-title function_ invoke__">convert_cyr_string</span></span><span> ( </span><span><span class="hljs-keyword">string</span></span><span> </span><span><span class="hljs-variable">$str</span></span><span> , </span><span><span class="hljs-keyword">string</span></span><span> </span><span><span class="hljs-variable">$from</span></span> , </span><span><span class="hljs-keyword">string</span></span><span> </span><span><span class="hljs-variable">$to</span></span> ) : </span><span><span class="hljs-keyword">string</span></span><span>
</span></span>$str: The string to be converted.
$from: The source encoding, such as 'koi8-r' or 'win-1251'.
$to: The target encoding, such as 'koi8-r' or 'utf-8'.
For example, if you have a text encoded in KOI8-R, you can convert it to UTF-8 using convert_cyr_string:
<span><span><span class="hljs-variable">$text</span></span><span> = </span><span><span class="hljs-string">"Привет мир"</span></span><span>; </span><span><span class="hljs-comment">// KOI8-R encoding</span></span><span>
</span><span><span class="hljs-variable">$converted_text</span></span><span> = </span><span><span class="hljs-title function_ invoke__">convert_cyr_string</span></span><span>(</span><span><span class="hljs-variable">$text</span></span>, </span><span><span class="hljs-string">'koi8-r'</span></span>, </span><span><span class="hljs-string">'utf-8'</span></span>);
</span><span><span class="hljs-keyword">echo</span></span> </span><span><span class="hljs-variable">$converted_text</span></span>; </span><span><span class="hljs-comment">// Output: Привет мир</span></span><span>
</span></span>Beyond encoding conversion, sometimes you need to clean unnecessary characters from a string, such as special symbols, line breaks, or unrecognized encodings. In these cases, str_replace can help replace or remove them.
The str_replace function in PHP is used for string replacement. Its prototype is:
<span><span><span class="hljs-title function_ invoke__">str_replace</span></span><span>( </span><span><span class="hljs-keyword">mixed</span></span> </span><span><span class="hljs-variable">$search</span></span> , </span><span><span class="hljs-keyword">mixed</span></span> </span><span><span class="hljs-variable">$replace</span></span> , </span><span><span class="hljs-keyword">mixed</span></span> </span><span><span class="hljs-variable">$subject</span></span> ) : </span><span><span class="hljs-keyword">mixed</span></span><span>
</span></span>$search: The character or string to search for.
$replace: The replacement character or string.
$subject: The original string where replacements will occur.
For example, you can use str_replace to replace all line breaks in a string with spaces, or to remove extra whitespace:
<span><span><span class="hljs-variable">$text</span></span><span> = </span><span><span class="hljs-string">"Hello, \nWorld! \tThis is PHP."</span></span><span>;
</span><span><span class="hljs-variable">$cleaned_text</span></span><span> = </span><span><span class="hljs-title function_ invoke__">str_replace</span></span><span>(</span><span><span class="hljs-keyword">array</span></span>(</span><span><span class="hljs-string">"\n"</span></span>, </span><span><span class="hljs-string">"\t"</span></span>), </span><span><span class="hljs-string">' '</span></span>, </span><span><span class="hljs-variable">$text</span></span>);
</span><span><span class="hljs-keyword">echo</span></span> </span><span><span class="hljs-variable">$cleaned_text</span></span>; </span><span><span class="hljs-comment">// Output: Hello, World! This is PHP.</span></span><span>
</span></span>When you need to both convert encodings and clean unnecessary characters, convert_cyr_string and str_replace can work well together. Suppose you have a text with Cyrillic characters that also contains invalid characters, such as extra line breaks or non-printable symbols—you can first use convert_cyr_string for encoding conversion, and then apply str_replace to clean up unwanted characters.
For example, if you have text encoded in KOI8-R with line breaks and extra spaces, here’s how you could clean it:
<span><span><span class="hljs-variable">$text</span></span><span> = </span><span><span class="hljs-string">"Привет \nмир! \tЭто \tтестовый \nтекст."</span></span><span>;
</span><span><span class="hljs-comment">// First convert KOI8-R encoding to UTF-8</span></span><span>
</span><span><span class="hljs-variable">$converted_text</span></span><span> = </span><span><span class="hljs-title function_ invoke__">convert_cyr_string</span></span><span>(</span><span><span class="hljs-variable">$text</span></span>, </span><span><span class="hljs-string">'koi8-r'</span></span>, </span><span><span class="hljs-string">'utf-8'</span></span>);
</span><span><span class="hljs-comment">// Then use str_replace to remove extra spaces and line breaks</span></span><span>
</span><span><span class="hljs-variable">$cleaned_text</span></span><span> = </span><span><span class="hljs-title function_ invoke__">str_replace</span></span><span>(</span><span><span class="hljs-keyword">array</span></span>(</span><span><span class="hljs-string">"\n"</span></span>, </span><span><span class="hljs-string">"\t"</span></span>), </span><span><span class="hljs-string">' '</span></span>, </span><span><span class="hljs-variable">$converted_text</span></span>);
</span><span><span class="hljs-keyword">echo</span></span> </span><span><span class="hljs-variable">$cleaned_text</span></span>; </span><span><span class="hljs-comment">// Output: Привет мир! Это тестовый текст.</span></span><span>
</span></span>By following this approach, you first solve encoding issues with convert_cyr_string, then clean unwanted characters with str_replace, resulting in clean, standardized text.
While convert_cyr_string itself is not directly used for text cleanup, when combined with other functions such as str_replace, it becomes an effective way to clean and normalize text—especially when handling character sets in different encodings. By combining these functions, you can easily convert encodings and clean characters, ensuring consistency across different systems or platforms.
Hopefully, today’s explanation helps you better understand how to use convert_cyr_string and str_replace to handle text encoding and cleanup!
