You want to find a pattern (regular expression) within a string of text.
Use preg_match() and preg_match_all(). The difference between these two functions is that preg_match() stops searching after the first match, whereas preg_match_all() will continue searching until the end of the string, saving what it finds in an array.
<html>
<head>
<title>PHP</title>
<meta Name="Author" Content="Hann So">
</head>
<body>
<p>
<?php
if (isset($_POST['submit'])) {
process_form();
}
else {
display_form();// display form for the first time
}
function display_form() {
echo <<<HTML
<form action = "$_SERVER[SCRIPT_NAME]" method="post">
Regular Expression Pattern (include the delimiter):<br />
<input type="text" name="pattern" value="/world/" /><br />
Text:<br />
<input type="text" name="text" size="70" value="Welcome to the world of PHP. The Internet world is full of challenges." /><br />
<input type="submit" name="submit" value="Check" />
</form>
<table border>
<tr bgcolor="lightcyan">
<th align="left">Regular Expression</th>
<th align="left">Text</th>
</tr>
<tr>
<td>/love/</td>
<td>My lovely gloves are worse for wear, Love.
</td>
</tr>
</table>
HTML;
}
function process_form() {
// stripslashes and trim the strings
$pattern = stripslashes(trim($_POST['pattern']));
$text = trim($_POST['text']);
echo "The result of checking <br /><font color=red>$pattern</font><br />
against<br /><font color=red>$text</font><br /> is:<br />";
// match the pattern
if (preg_match($pattern, $text, $matches)) {
echo "$pattern was matched. <br />";
}
else {
echo "$pattern was not matched. <br />";
}
echo "<br />The matches array contains:<br />";
foreach ($matches as $key =>$values) {
echo $key, " => ", $values, "<br />";
}
echo "<br /><a href=\"$_SERVER[SCRIPT_NAME]\">Check again?</a>";
}
?>
</p>
</body>
</html>
|
The preg_match_all() creates an array of all the patterns matched in the string, not just the first one, and returns the number of times it matched the pattern.
<html>
<head>
<title>PHP</title>
<meta Name="Author" Content="Hann So">
</head>
<body>
<p>
<?php
if (isset($_POST['submit'])) {
process_form();
}
else {
display_form();// display form for the first time
}
function display_form() {
echo <<<HTML
<form action = "$_SERVER[SCRIPT_NAME]" method="post">
Regular Expression Pattern (include the delimiter):<br />
<input type="text" name="pattern" value="/world/" /><br />
Text:<br />
<input type="text" name="text" size="70"
value="Welcome to the world of PHP. The Internet world is full of challenges." /><br />
<input type="submit" name="submit" value="Check" />
</form>
HTML;
}
function process_form() {
// stripslashes and trim the strings
$pattern = stripslashes(trim($_POST['pattern']));
$text = trim($_POST['text']);
echo "The result of checking <br /><font color=red>$pattern</font><br />
against<br /><font color=red>$text</font><br /> is:<br />";
// match the pattern
if (preg_match_all($pattern, $text, $matches)) {
echo "$pattern was matched. <br />";
}
else {
echo "$pattern was not matched. <br />";
}
echo "<br />The matches array contains:<br />";
// The matches are stored in the first element of the array
foreach ($matches[0] as $key =>$values) {
echo $key, " => ", $values, "<br />";
}
echo "<br /><a href=\"$_SERVER[SCRIPT_NAME]\">Check again?</a>";
}
?>
</p>
</body>
</html>
|