Regular Expressions 101

Explanation
Pro

Positive Lookbehind(?<=author=\")

author=the literal text author= (case sensitive)

\"the literal " (34₁₀ / 42₈ / 22₁₆)

Negated Character Class[^\"]+

+matches at least one character outside the set below:

\"the literal " (34₁₀ / 42₈ / 22₁₆)

Detailed match information will be displayed here automatically.

25 tokens

(?<=author=\")[^\"]+

New

<pre>
    <book category="CHILDREN">
      <details title="Harry Potter" author="J K. Rowling">
    </book>
</pre>

xyzName

<pre>
    <book category="CHILDREN">
      <details title="Harry Potter" author="J K. Rowling">
    </book>
</pre>