简单教程
提交运行
代码编辑器：
<?php $str = "This is nice"; echo strlen($str)."<br>"; echo substr_count($str,"is"), "<br>"; echo substr_count($str,"is",2),"<br>"; echo substr_count($str,"is",3),"<br>"; echo substr_count($str,"is",3,3), "<br>";
运行结果：