const regex = new RegExp('(<tr>\\s*(<th>((?!<tr>).)*</th>)+\\s*</tr>)', 'igs')
const str = `<table>
<tr>
<th>header21</th>
<th>header22</th>
<th>header23</th>
</tr>
<tr>
<td>body1</td>
<td>body2</td>
<td>body3</td>
</tr>
</table>
<table>
<tr>
<th>header21</th>
<th>header22</th>
<th>header23</th>
</tr>
<tr>
<td>body1</td>
<td>body2</td>
<td>body3</td>
</tr>
</table>
`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions