const regex = /(?:(?<= [+][1-9])|(?<= [1-9])|(?<= ))([2-9][0-9]{9})\b/gi;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(?:(?<= [+][1-9])|(?<= [1-9])|(?<= ))([2-9][0-9]{9})\\b', 'gi')
const str = `abcd +12125551212 xyz should match starting at 212
abcd +2125551212 xyz should NOT match (+ sign only)
abcd 2125551212 xyz match OK!
abcd+12125551212 xyz should NOT match (no white space at start)
abcd 12125551212 xyz should match starting at 212
`;
// 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