XPath and XSLT

const parse = (s) => new DOMParser().parseFromString(s, 'application/xml');
const xml = parse('<menu><dish price="9">Satay</dish><dish price="12">Curry</dish></menu>');
console.log(xml.evaluate('sum(//dish/@price)', xml, null, XPathResult.NUMBER_TYPE).numberValue);
const xsl = parse(`<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/menu"><ul><xsl:for-each select="dish">
    <li><xsl:value-of select="."/> $<xsl:value-of select="@price"/></li>
  </xsl:for-each></ul></xsl:template></xsl:stylesheet>`);
const processor = new XSLTProcessor();
processor.importStylesheet(xsl);
console.log(processor.transformToFragment(xml, document).firstChild.textContent.trim());

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XSLTProcessor and XSLT Processing Instructions have been deprecated by all browsers. These
  features will
be removed from this browser soon. See https://chromestatus.com/feature/4709671889534976.
Satay $9
Curry $12