Regular Expressions 101

Positive Lookbehind(?<=<table>)

<table>the literal text <table> (case insensitive)

\s*any whitespace character, repeated any number of times

<tr>the literal text <tr> (case insensitive)

\s*any whitespace character, repeated any number of times

<td>the literal text <td> (case insensitive)

Group 1([a-z0-9 ]*)

Character Class[a-z0-9 ]*

*matches any number of characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

the literal (32₁₀ / 40₈ / 20₁₆)

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

td>the literal text td> (case insensitive)

\s*any whitespace character, repeated any number of times

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

tr>the literal text tr> (case insensitive)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

s modifier: single line. Allows a dot to match line terminators

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?<=<table>)\s*<tr>\s*<td>([a-z0-9 ]*)<\/td>\s*<\/tr>

New

<table>
    <tr>
        <td>Text A</td>
    </tr>
    <tr>
        <td>
            <table>  <!-- Notice this is an inner scope table -->
                <tr>
                    <td>Text B</td>
                </tr>
            </table>
        </td>
    </tr>
</table>

<table>
    <tr>
        <td>
            <table> <!-- Notice this is an inner scope table -->
                <tr>
                    <td>Text C</td>
                </tr>
            </table>
        </td>
    </tr>
</table>

<table>
    <tr>
        <td>Text D</td>
    </tr>
</table>