files/en-us/web/api/cssstylesheet/cssrules/index.md
{{APIRef("CSSOM")}}
The read-only {{domxref("CSSStyleSheet")}} property
cssRules returns a live {{domxref("CSSRuleList")}} which
provides a real-time, up-to-date list of every CSS rule which comprises the
stylesheet. Each item in the list is a {{domxref("CSSRule")}} defining a single
rule.
A live-updating {{domxref("CSSRuleList")}} containing each of the CSS rules making up the stylesheet. Each entry in the rule list is a {{domxref("CSSRule")}} object describing one rule making up the stylesheet.
Individual rules within the stylesheet can then be accessed by index:
const ruleList = document.styleSheets[0].cssRules;
for (let i = 0; i < ruleList.length; i++) {
processRule(ruleList[i]);
}
Rules can also be accessed using {{jsxref("Statements/for...of", "for...of")}}:
const ruleList = document.styleSheets[0].cssRules;
for (const rule of ruleList) {
processRule(rule);
}
However, because CSSRule is not a proper array, you can't use
{{jsxref("Array.forEach", "forEach()")}}.
{{Specifications}}
{{Compat}}