const regex = /\[(.+?)(?<!(?<!\\)\\{2})\]/mg;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('\\[(.+?)(?<!(?<!\\\\)\\\\{2})\\]', 'mg')
const str = `+------------------+----------------+
| Input | Output |
+------------------+----------------+
| [B] | B |
| [B][C][D] | B |
| [hello\\t\\tworld] | hello\\t\\tworld |
| [hello\\n\\nworld] | hello\\n\\nworld |
| [\\\\]] | \\\\] |
| [\\\\\\\\] | \\\\\\\\ |
| [x[y\\\\]z][foo] | x[y\\\\]z |
+------------------+----------------+`;
// 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