const regex = /\b\d{4}\b/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('\\b\\d{4}\\b', 'gm')
const str = ` '2025',
'2150 is the year to match',
'the year is 2030 see ref 2099662',
'Should match the year here YEAR_2140 even though it has non numric chars preceeding it',
'Should match the year at the end of a string like this - 2140',
'ref 2099662 the year is 2140. And there is another sentence',
'ref 2099662 the end of the string is the year 2140',
'There is no year here 2055667'`;
// 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