Removing child nodes from DOM table removing only alternate children

Question

I am using PHP and I have an HTML string that contains a string. I need to delete all rows of the table (In reality, there would be some logic to check if to delete the row but for now I am deleting all the rows).

I am trying to delete all the rows from the table but only alternate rows are getting deleted.

$html_string = <<
   
   
      
         
            
               Col1
               Col2
               Col3
               Col4
               Col5;
            
         
         
            
               
               Item 1
               
               
               
            
            
               
               Item 2
               
               
               
            
            
               
               Item 3
               
               
               
            
            
               
               Item 4
               
               
               
            
         
      
   

HTML

$doc = new DOMDocument();
$doc->loadHTML($html_string);
$table = $doc->getElementsByTagName('table')[0];
$trs = $table->getElementsByTagName('tr');
for( $x=1; $xparentNode->removeChild($trs[$x]);
}

//var_dump($doc->saveHTML()); // to check output of the above code

Actual Result after doing above:

Col1    Col2    Col3    Col4    Col5
        Item 2          
        Item 4

Expected Result:

Col1    Col2    Col3    Col4    Col5

user_13060981 · Answer

You problem is about understanding this part of code

$trs[$x]->parentNode->removeChild($trs[$x]);

When you remove an element in this way the element will remove from the $trs and then reindex in indexes for example look and this example

elements
    1 -> sub element 1
    2 -> sub element 2
    3 -> sub element 3

When you remove the first one it will be like this

elements
    1 -> sub element 2
    2 -> sub element 3

And now you again need to remove the element with index 1
so you should change this code to sth like this

$trs[1]->parentNode->removeChild($trs[1]);

And your final code will be like this

$html_string = '

   
   
      
         
            
               Col1
               Col2
               Col3
               Col4
               Col5;
            
         
         
            
               
               Item 1
               
               
               
            
            
               
               Item 2
               
               
               
            
            
               
               Item 3
               
               
               
            
            
               
               Item 4
               
               
               
            
         
      
   
';

$doc = new DOMDocument();
$doc->loadHTML($html_string);
$table = $doc->getElementsByTagName('table')[0];
$trs = $table->getElementsByTagName('tr');
$trCount = count($trs) - 1;
for( $x=0; $x < $trCount; $x++ ) {
      $trs[1]->parentNode->removeChild($trs[1]);
}

print_r($doc->saveHTML());

Removing child nodes from DOM table removing only alternate children

1 Answers