const regex = /@media\b[^{]*({(?>[^{}]++|(?1))*})/g;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('@media\\b[^{]*({(?>[^{}]++|(?1))*})', 'g')
const str = `@media only screen {
p {
color:red;
}
}
@media only screen and (max-width: 596px) {
p {
color:blue;
}
@media only screen {
p {
color:red;
}
}
}
@media only screen {
}
img {
display: block;
}
@media only screen and (max-width: 240px) {
p {
color:green;
}
}
p {
font-weight: normal;
}`;
// 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