const regex = /^(?=[A-Za-z0-9][A-Za-z0-9@._%+-]{5,253}$)[A-Za-z0-9._%+-]{1,64}@(?:(?=[A-Za-z0-9-]{1,63}\.)[A-Za-z0-9]+(?:-[A-Za-z0-9]+)*\.){1,8}[A-Za-z]{2,63}$/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('^(?=[A-Za-z0-9][A-Za-z0-9@._%+-]{5,253}$)[A-Za-z0-9._%+-]{1,64}@(?:(?=[A-Za-z0-9-]{1,63}\\.)[A-Za-z0-9]+(?:-[A-Za-z0-9]+)*\\.){1,8}[A-Za-z]{2,63}$', 'gm')
const str = `Format: minimum 2 characters @ minimum 3 characters . 2 - 63 characters
the g modifier let's us match multiple times in one string. the m modifier is useful here because it lets us treat each line as a seperate entry. Though in practice you probably dont need it for a simple one line email field
^(?=[A-Z0-9][A-Z0-9@._%+-]{5,253}+\$)[A-Z0-9._%+-]{1,64}+@(?:(?=[A-Z0-9-]{1,63}+\\.)[A-Z0-9]++(?:-[A-Z0-9]++)*+\\.){1,8}+[A-Z]{2,63}+\$
שדגכ@שדגכ
דגכ
אלפ@גכדץ.בםצ
Jim@stuff.co.uk
Jim@google.com
Henry@h.com
Joe @m.net
Joe@m.net
Joe@mo.net
Joe@sam.net
a@sam.net
mo@sam.org
12@sam.org
Jon@sam.c
Jon@sam.co
`;
// 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