PHP删除字符前的一切

Question

I have following mysql php array result.

while($row = mysql_fetch_array($retval, MYSQL_ASSOC))
{
echo '<tr>';
echo "<td> {$row['cust']} </td>".
     "<td> {$row['manu']} </td>".
     "<td> {$row['model']} </td>".
     "<td> {$row['serial']} </td>".
     "<td> {$row['capacity']} </td>".
     "<td> {$row['firmware']} </td>".
     "<td> {$row['deviceid']} </td>".
     "<td> {$row['ataver']} </td>".
     "<td> {$row['ltime']} </td>".
     "<td> {$row['date']} </td>".
     "<td> {$row['ourref']} </td>".
     "<td> {$row['result']} </td>";


/**                     foreach($row as $key=>$value) {
                                echo '<td>',$value,'</td>';
                        }*/
                        echo '</tr>';

"<td> {$row['capacity']} </td>". array holds information like

250000000000 bytes [250 GB]
400000000000 bytes [400 GB]
500000000000 bytes [500 GB]

I want to delete everything including bytes.

So the desired output would look like

250 GB
400 GB
500 GB

How can i achieve this using above code?

Thanks well in advance.

Answer 1

It's quite simple, look here :

$String = "250000000000 bytes [250 GB]";

$String2 = substr($String, 0, 3); // take the first 3 caracteres

$result = $String2." GB"; // Just add GB after
echo $result;

Just replace "<td> {$row['capacity']} </td>". with the fallowing

   "<td>".substr($String, 0, 3)." GB</td>".

Answer 2

You can use regular expressions to achieve this:

preg_match('/\[(.*?)\]/', $row['capacity'], $matches);
if (isset($matches[1])) {
    $row['capacity'] = $matches[1];
}
echo "<td> {$row['capacity']} </td>";

Answer 3

There are many ways to do this, I'd use a regex to capture everything inbetween the brackets.

$string = '250000000000 bytes [250 GB]
400000000000 bytes [400 GB]
500000000000 bytes [500 GB]';
preg_match_all('~\[(.*?)\]~', $string, $sizes);
print_r($sizes[1]);

Output:

Array
(
    [0] => 250 GB
    [1] => 400 GB
    [2] => 500 GB
)

Regex101 Demo: https://regex101.com/r/zR6pU1/1

The . is any character, the * is zero or more occurrences of any character and the ? stops at the first occurrence of the next character. The + might be a better quantifier so that you are sure that there is something in there. The + is one or more occurrences.

With the + quantifier,

$string = '250000000000 bytes [250 GB]
400000000000 bytes [400 GB]
500000000000 bytes [500 GB]';
preg_match_all('~\[(.+?)\]~', $string, $sizes);
print_r($sizes[1]);

If you wanted to be stricter you could even do:

$string = '250000000000 bytes [250 GB]
400000000000 bytes [400 GB]
500000000000 bytes [500 GB]';
preg_match_all('~\[(\d+ [MKG]B)\]~', $string, $sizes);
print_r($sizes[1]);

Which would match any numbers a space and then KB, MB, or GB. The [] is a character class allowing any of the literal characters inside to be present.

Answer 4

You can use:

$str = preg_replace('[[:digit:]]+ Bytes ', "", $str);

https://regex101.com/r/fE7nO5/1

Then str_replace to replace the [] characters.

$str = str_replace('[', ' ', $str);
$str = str_replace(']', ' ', $str);
$str = trim($str);

Edit: You can also do it with one regex:

$str = preg_replace('[[:digit:]]+ Bytes |\[|\]', "", $str);

https://regex101.com/r/fE7nO5/2