how to change null value if tag not available using regex app script to scrap html-CodePudding

how to change null value if tag not available using regex app script to scrap html.

the code has multi class and multi td tag:

the HTML:

<tr dir="row">
  <td class='' data='#' >
                                    -
                                </td>
  <td class='' data='#' >
                                    -
                                </td>

</tr>

<tr dir="row">

  <a class='link'  href='http://www.facebook.com' target='_blank'>
  </a>

  <td class='' data='#' >
                                    -
                                </td>

</tr>

my code regex:

rows = ****************
url= *******************

for(var i = 0; i < 2; i  ){

    //var name = rows[i].match(table)
 }

if use this code is return:

1:50 PM Notice  Execution started
9:41:51 PM  Info    null
9:41:51 PM  Info    [www.facebook.com]
9:41:51 PM  Notice  Execution completed

I want to get just facebook value I use:

for(var i = 0; i < 2; i  ){

        //var name = rows[i].match(table)[0] // to first value OR [1] to get second value
     }

I get the error:

10:08:02 PM Notice  Execution started
10:08:04 PM Error   
TypeError: Cannot read property '0' of null

because the tag <a class= can't find in first but find in second: how can I use it without this error

CodePudding user response：

Change this:

var name = rows[i].match(table)[0]

to:

var match = rows[i].match(table) 
var name = match ? match[0] : ""

Reason: match(table) is returning null sometimes