const regex = /^(?P<qualifier>[+?~-])?(?P<is_a>a)(?:[:])?(?P<a_mechanism>.+)?/gim;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('^(?P<qualifier>[+?~-])?(?P<is_a>a)(?:[:])?(?P<a_mechanism>.+)?', 'gim')
const str = `a
a:example.com
+a:example.com
a:mailers.example.com
~a:mailers.example.com
a/24
-a:offsite.example.com/24
?a:example.com/24
+mx:mail.example.com
mx
ip4:192.168.11.0/32`;
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