将CSV读入HTML表-忽略特定列

Question

I have code that opens a CSV file and loops through every row of data and creates a table from it.

There are specific columns I'd like to ignore. How do I change my code to not display certain columns?

    <?php
    echo "<table>\n\n";
    $f = fopen("users.csv", "r");
    while (($line = fgetcsv($f)) !== false) {
            echo "<tr>";
            foreach ($line as $cell) {
                    echo "<td>" . htmlspecialchars($cell) . "</td>";
            }
            echo "</tr>\n";
    }
    fclose($f);
    echo "\n</table>";

Answer 1

If you base on the indexes of the column, you could do something like that for example :

<?php
    echo "<table>\n\n";
    $f = fopen("users.csv", "r");
    $idsColumnsNotWanted = array(3,4,20);  //indexes of columns you don't want to display
    while (($line = fgetcsv($f)) !== false) {
            echo "<tr>";
            $numcolumn=0;
            foreach ($line as $cell) {
                if(!in_array($numcolumn,$idsColumnsNotWanted)
                    echo "<td>" . htmlspecialchars($cell) . "</td>";
                $numcolumn++;
            }
            echo "</tr>\n";
    }
    fclose($f);
    echo "\n</table>";

Answer 2

If your CSV file is big, the in_array() function can slow things down a lot.

<?php
$exclude = array(3 => 3, 4 => 4, 20 => 20);
echo "<table>\n\n";
$f = fopen("users.csv", "r");
while (($line = fgetcsv($f)) !== false) {
        echo "<tr>";
        foreach ($line as $index => $cell) {
           if ( ! isset($exclude[ $index ]) )
                echo "<td>" . htmlspecialchars($cell) . "</td>";
        }
        echo "</tr>\n";
}
fclose($f);
echo "\n</table>";

If you want it to work the other way around use:

<?php
$include = array(3 => 3, 4 => 4, 20 => 20);
echo "<table>\n\n";
$f = fopen("users.csv", "r");
while (($line = fgetcsv($f)) !== false) {
        echo "<tr>";
        foreach ($line as $index => $cell) {
           if ( isset($include[ $index ]) )
                echo "<td>" . htmlspecialchars($cell) . "</td>";
        }
        echo "</tr>\n";
}
fclose($f);
echo "\n</table>";