const regex = new RegExp('<mrow[^>]*>\\(?((?:(?!</?mrow\\b[^>]*>).)*?)\\)?</mrow>', 'gm')
const str = `<msub><mi>y</mi><mrow>(<mi>n</mi><mo>+</mo><mn>1</mn>)</mrow></msub><mo>=</mo><msub><mi>y</mi><mrow>(<mi>n</mi><mo>-</mo><mn>1</mn>)</mrow></msub><mo>*</mo><msup><mrow>(<msub><mi>y</mi><mi>n()</mi></msub>)</mrow><mrow><mn>2</mn></mrow></msup>
<mrow>(<mn>1000001</mn>)</mrow>`;
// 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