Example of a PHP regular to extract/replace/Add ALT tags to a picture

Example

$arcrow [' title ']= ' article titles ';
$arcrow [' content ']= ' article body ';

$pattern = "/(]*?alt=[^<>]*?>)) (.*?>)/is "; Add an alt label to a picture
$replacement = "\$1 alt= '". Strip_tags ($arcrow [' title ']). "' \$2";
$arcrow [' content '] = preg_replace ($pattern, $replacement, $arcrow [' content ']);

PHP instance:

Use regular expressions to replace substrings (Alt tags) of strings (picture labels) with the following code:
<?php
$str =<<<start
<a href= "http://www.111cn.net" target= "_blank" alt= "1231dsfdsfds" >aaa</a>
Start
$pattern = '/alt= ' \d+[a-z]+\ '/I ';
$replace = ';
$result =preg_replace ($pattern, $replace, $STR);
echo $result;
?>
Output results <a href= "http://www.111cn.net" target= "_blank" >aaa</a>
Remove the contents of ALT and Alt inside.

Example

PHP regular fetch img tag alt src width Heigh property

<?php
/* Regular take picture of any attribute in the IMG tag * *
$word = "<p height=" align= "Cenetr" >111 22</p> <div style=" float:left; > Chinese </div> ';
Take the whole picture code
Preg_match ('//is ', $word, $matches);
echo $matches [0];//results:

$word = ' <p height= ' align= "Cenetr" >111 22</p> <div style=" float:left; > Chinese </div> ';
Take width
Preg_match ('//i ', $word, $matches);
echo $matches [1];
Take height
Preg_match ('//i ', $word, $matches);
echo $matches [1];
Take SRC
Preg_match ('//i ', $word, $matches);
echo $matches [1];
/* Regular replacement Remove or change any attribute in the image img Tag ***************************************************************/
$str = ' <p height= "align=" Cenetr ">111 22</p> <div style= "float:left;"  > Chinese </div><p height= align= "Cenetr" >31313 224344</p> <div style= "float:left;" >1212121</div> ';

Change the src attribute (where the original src= "/upload/images/bbb.jpg" is changed to Src= "/upload/_thumbs/images/bbb.jpg")
Print Preg_replace ('/()/I ', "${1}_thumbs/images/${3}", $STR);

/* Change src attribute,
Here the original src= "/upload/images/bbb.jpg" changed to Src= "/upload/_thumbs/images/bbb.jpg", and discard width and height
(for example, you want to display thumbnails in the foreground, but the database tutorial stores the path of the original image.) Why do you want to abandon the width of the high? You thumbnails Ah! or the original image of the width of the height, how will???)
*/
Print Preg_replace ('/(/i ', "${1} ${2}_thumbs/images/${3}>", $STR);