const regex = /(?(DEFINE) # start DEFINE block
# pre-define quant subroutine
(?<quant>many|some|five)
# pre-define adj subroutine
(?<adj>blue|large|interesting)
# pre-define object subroutine
(?<object>cars|elephants|problems)
# pre-define noun_phrase subroutine
(?<noun_phrase>(?&quant)\ (?&adj)\ (?&object))
# pre-define verb subroutine
(?<verb>borrow|solve|ressemble)
) # end DEFINE block
##### The regex matching starts here #####
(?&noun_phrase)\ (?&verb)\ (?&noun_phrase)/g;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(?(DEFINE) # start DEFINE block
# pre-define quant subroutine
(?<quant>many|some|five)
# pre-define adj subroutine
(?<adj>blue|large|interesting)
# pre-define object subroutine
(?<object>cars|elephants|problems)
# pre-define noun_phrase subroutine
(?<noun_phrase>(?&quant)\\ (?&adj)\\ (?&object))
# pre-define verb subroutine
(?<verb>borrow|solve|ressemble)
) # end DEFINE block
##### The regex matching starts here #####
(?&noun_phrase)\\ (?&verb)\\ (?&noun_phrase)', 'g')
const str = `five blue elephants solve many interesting problems
many large problems ressemble some interesting cars`;
// 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