程序如此灵动！

昨天想统计一下tianya帖子的回复数，就想统计一下一段字符中某段字符出现的次数，就百度了一下下，当然找到了这个函数拉~~~substr_count()
官方说明：http://cn.php.net/manual/zh/function.substr-count.php
hihi，here we go~~~~~~~~~

说明:

int substr_count ( string $haystack, string
$needle [, int $offset [, int $length]] )

substr_count() returns the number of times the
needle substring occurs in the haystack string. please note that
needle is case sensitive.

贴个例子比什么都说明问题。见下：

<br /> <?php<br /> $text = ‘this is a test’;<br /> echo strlen($text); // 14</p> <p>echo substr_count($text, ‘is’); // 2</p> <p>// the string is reduced to ’s is a test’, so it prints 1<br /> echo substr_count($text, ‘is’, 3);</p> <p>// the text is reduced to ’s i’, so it prints 0<br /> echo substr_count($text, ‘is’, 3, 3);</p> <p>// generates a warning because 5+10 > 14<br /> echo substr_count($text, ‘is’, 5, 10);</p> <p>// prints only 1, because it doesn’t count overlapped subtrings<br /> $text2 = ‘gcdgcdgcd’;<br /> echo substr_count($text2, ‘gcdgcd’);<br /> ?><br />