正则替换问题 多关键字加亮

PHP code

$k=array("i","n");$row="iphone";$row = preg_replace("/($k[0])/i", "<font color=red><b>\\1</b></font>", $row);$row = preg_replace("/($k[1])/i", "<font color=red><b>\\1</b></font>", $row);echo $row;//输出 nt color=red>int>phone//怎么样才能让关键字也就是$k里面的字母变为红色的？不重复替换？

PHP code

$k=array("i","n");$p= join('',$k);$row="iphone";echo  preg_replace("/[".$p."]/i", "<font color=red><b>\\0</b></font>", $row);