Difference between revisions of "Number of characters"

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<table border="1" class="wikitable sortable">
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#REDIRECT [[Count number of characters]]
<tr>
 
<th>String example</th>
 
<th>Number of characters</th>
 
<th>Number of bytes</th>
 
</tr>
 
<tr>
 
<td>fox</td>
 
<td>3</td>
 
<td>3</td>
 
</tr>
 
<tr>
 
<td>The quick brown fox jumps over the lazy dog</td>
 
<td>43</td>
 
<td>43</td>
 
</tr>
 
<tr>
 
<td>狐</td>
 
<td>1</td>
 
<td>3</td>
 
</tr>
 
<tr>
 
<td>象</td>
 
<td>1</td>
 
<td>3</td>
 
</tr>
 
<tr>
 
<td>🐘</td>
 
<td>1</td>
 
<td>4</td>
 
</tr>
 
<tr>
 
<td>敏捷的棕毛狐狸從懶狗身上躍過</td>
 
<td>14</td>
 
<td>28</td>
 
</tr>
 
</table>
 
 
 
== PHP ==
 
* PHP: [https://www.php.net/manual/en/function.strlen.php strlen] & [http://php.net/mb_strlen PHP mb_strlen function]
 
<pre>
 
// number of characters
 
echo mb_strlen("狐", 'UTF-8') . PHP_EOL; // return 1
 
echo mb_strlen("《王大文 Dawen》", 'UTF-8') . PHP_EOL; // return 11
 
 
 
// string length (number of bytes)
 
echo strlen("狐") . PHP_EOL; // return 3
 
echo strlen("《王大文 Dawen》") . PHP_EOL; // return 21
 
</pre>
 
 
 
== MySQL ==
 
* MySQL: [http://www.w3resource.com/mysql/string-functions/mysql-char_length-function.php MySQL CHAR_LENGTH() function]
 
<PRE>
 
// number of characters
 
SELECT CHAR_LENGTH("狐"); /* return 1 */
 
SELECT CHAR_LENGTH("《王大文 Dawen》"); /* return 11 */
 
 
 
// number of bytes
 
SELECT LENGTH("狐"); /* return 3 */
 
SELECT LENGTH("《王大文 Dawen》"); /* return 21 */
 
</PRE>
 
* [https://dev.mysql.com/doc/refman/8.0/en/char.html MySQL :: MySQL 8.0 Reference Manual :: 11.4.1 The CHAR and VARCHAR Types] e.g. {{kbd | key=<nowiki>VARCHAR(5)</nowiki>}} or {{kbd | key=<nowiki>CHAR(5)</nowiki>}} means can hold up to 5 characters.
 
 
 
 
 
== SQLite ==
 
[https://www.sqlitetutorial.net/sqlite-functions/sqlite-length/#targetText=SQLite%20Length,returns%20the%20number%20of%20bytes. Length] function
 
<PRE>
 
SELECT LENGTH("狐"); /* return 1 */
 
SELECT LENGTH("《王大文 Dawen》"); /* return 11 */
 
</PRE>
 
 
 
== Excel ==
 
* Excel: [https://support.office.com/en-us/article/len-lenb-functions-29236f94-cedc-429d-affd-b5e33d2c67cb LEN, LENB functions] / [https://support.office.com/zh-tw/article/LEN%E3%80%81LENB-%E5%87%BD%E6%95%B8-29236f94-cedc-429d-affd-b5e33d2c67cb LEN、LENB 函數] {{exclaim}} Result of the function {{kbd | key=LENB}} is not the same with the result in other programming language.
 
<pre>
 
// number of characters
 
=LEN("狐") // return 1
 
=LEN("《王大文 Dawen》") // return 11
 
 
 
// number of bytes
 
=LENB("狐") // return 2
 
=LENB("《王大文 Dawen》") // return 16
 
</pre>
 
 
 
* [http://string-functions.com/length.aspx Calculate String Length Online]
 
* [https://stackoverflow.com/questions/5290182/how-many-bytes-does-one-unicode-character-take string - How many bytes does one Unicode character take? - Stack Overflow]
 
 
 
[[Category:Data Science]] [[Category:PHP]] [[Category:MySQL]] [[Category:Text file processing]]
 

Latest revision as of 19:02, 6 November 2019