使用PHP计算HTML表中的列

Question

I have a basic string with holds a html table. The table looks like this:

<TR>
    <TD>asdf, dfg</TD><TD>0915</TD><TD>0945</TD><TD></TD><TD>15</TD><TD>45</TD><TD></TD><TD>1315</TD>
</TR>
<TR>
    <TD>asdf, dfg</TD><TD>0915</TD><TD>0945</TD><TD></TD><TD>15</TD><TD>45</TD><TD></TD><TD>1315</TD>
</TR>
<TR>
    <TD>asdf, dfg</TD><TD>0915</TD><TD>0945</TD><TD></TD><TD>15</TD><TD>45</TD><TD></TD><TD>1315</TD>
</TR>
<TR>
    <TD>asdf, dfg</TD><TD>0915</TD><TD>0945</TD><TD></TD><TD>15</TD><TD>45</TD><TD></TD><TD>1315</TD>
</TR>       

How would I use PHP to determine how many columns this table has?

Answer 1

As others have mentioned, if you have guaranteed valid HTML, and the table is guaranteed to have equal length rows, you can use simple string manipulation. Split the string on <tr> , then count the number of <td> in each piece:

function count_table_columns($html) {
    $html = strtolower($html);
    $rows = split('<tr>', $html);
    foreach($rows as $row) {
        if(!trim($row)) { continue; }
        return substr_count($row, '<td>');
    }
}

If there is the possibility of malformed HTML, use an HTML parser to parse the table, then iterate through the <tr> nodes, and count the subnodes of type <td> .

Here's one HTML parser to consider: http://sourceforge.net/projects/simplehtmldom/

Answer 2

Count <TD> 's with substr_count() . If your string contains more than one row, then count <TR> 's and divide total number of <TD> 's by number of <TR> 's.

Answer 3

This is simplehtmldom code that basically gets the number of columns in the HTML table

$table = $html->find('table',0);

foreach($table->find('tr') as $tr)
               {
                   $c=0;
                   foreach($tr->find('td') as $td) $c++;    
                   if( $c>$largest OR !isset($largest) ) $largest = $c; 
               }

$largest will give you column count.