php preg_replace用特定值替换特定字符串

Question

我研究了以下例子

---

$copy_date = "Copyright 1999";
$copy_date = preg_replace("([0-9]+)", "2000", $copy_date);

 here any numeric will be replaced by 2000

---

但是在下面的例子中我很困惑!!

如何更换

宽度=＆＃34;任何＆＃34;价值280

想要替换

之后出现的任何内容

   width=" 

带

   width="280"

示例       宽度=＆＃34; 481＆＃34; 将是width =＆＃34; 280＆＃34;

另一个例子.....

 <iframe width="680" height="480" src="//www.youtube.com/embed/RTcgXcz-_G0" frameborder="0" allowfullscreen></iframe>

在preg_replace之后

应该成为

  <iframe width="280" height="200" src="//www.youtube.com/embed/RTcgXcz-_G0" frameborder="0" allowfullscreen></iframe>

Answer 1

使用它：

$copy_date = '<iframe width="680" height="480" src="//www.youtube.com/embed/RTcgXcz-_G0" frameborder="0" allowfullscreen></iframe>' ;
$pattern = '/width="\d+"/i' ;
$new_style = 'width="280"' ;
$new_copy_date = preg_replace($pattern, $new_style, $copy_date) ;

echo $new_copy_date;