sean Thu Dec 2 12:52:04 2004 EDT
Modified files:
/phpdoc/en/reference/strings/functions levenshtein.xml
Log:
added example
http://cvs.php.net/diff.php/phpdoc/en/reference/strings/functions/levenshtein.xml?r1=1.5&r2=1.6&ty=u
Index: phpdoc/en/reference/strings/functions/levenshtein.xml
diff -u phpdoc/en/reference/strings/functions/levenshtein.xml:1.5
phpdoc/en/reference/strings/functions/levenshtein.xml:1.6
--- phpdoc/en/reference/strings/functions/levenshtein.xml:1.5 Thu Oct 28
05:44:22 2004
+++ phpdoc/en/reference/strings/functions/levenshtein.xml Thu Dec 2
12:52:04 2004
@@ -1,9 +1,9 @@
<?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.5 $ -->
+<!-- $Revision: 1.6 $ -->
<!-- splitted from ./en/functions/strings.xml, last change in rev 1.12 -->
<refentry id="function.levenshtein">
<refnamediv>
- <refname>levenshtein</refname>
+ <refname>levenshtein</refname>
<refpurpose>
Calculate Levenshtein distance between two strings
</refpurpose>
@@ -48,14 +48,14 @@
insert, replace and delete operations needed to transform
<parameter>str1</parameter> into <parameter>str2</parameter>.
</para>
- <para>
+ <para>
A second variant will take three additional parameters that
define the cost of insert, replace and delete operations. This
is more general and adaptive than variant one, but not as
efficient.
</para>
<!-- Callback function not yet implemented, see bug #29552
- <para>
+ <para>
The third variant (which is not implemented yet) will be the most
general and adaptive, but also the slowest alternative. It will
call a user-supplied function that will determine the cost for
@@ -105,7 +105,7 @@
describing the cost for this particular operation, but it may
decide to use only some of the supplied arguments.
</para>
- <para>
+ <para>
The user-supplied function approach offers the possibility to
take into account the relevance of and/or difference between
certain symbols (characters) or even the context those symbols
@@ -116,6 +116,68 @@
</para>
-->
<para>
+ <example>
+ <title><function>levenshtein</function> example</title>
+ <programlisting role="php">
+<![CDATA[
+<?php
+// input misspelled word
+$myWord = 'carrrot';
+
+// array of words to check against
+$words = array('apple','pineapple','banana','orange',
+ 'radish','carrot','pea','bean','potato');
+
+// no shortest distance found, yet
+$shortest = -1;
+
+// loop through words to find the closest
+foreach ($words AS $word) {
+
+ // calculate the distance between the input word,
+ // and the current word
+ $thisLev = levenshtein($myWord, $word);
+
+ // check for an exact match
+ if ($thisLev == 0) {
+
+ // closest word is this one (exact match)
+ $closest = $word;
+ $shortest = 0;
+
+ // break out of the loop; we've found an exact match
+ break;
+ }
+
+ // if this distance is less than the next found shortest
+ // distance, OR if a next shortest word has not yet been found
+ if ($thisLev <= $shortest || $shortest < 0) {
+ // set the closest matchm, and shortest distance
+ $closest = $word;
+ $shortest = $thisLev;
+ }
+}
+
+echo "Input word: $myWord\n";
+if ($shortest == 0) {
+ echo "Exact match found: $closest\n";
+} else {
+ echo "Did you mean: $closest?\n";
+}
+
+?>
+]]>
+ </programlisting>
+ </example>
+ &example.outputs;
+ <screen>
+<![CDATA[
+Input word: carrrot
+Did you mean: carrot?
+]]>
+ </screen>
+ </para>
+ <para>
See also <function>soundex</function>,
<function>similar_text</function>, and
<function>metaphone</function>.
