regex email

const pattern = /^[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}$/i;

// Test a string
console.log(pattern.test("user@example.com")); // true
console.log(pattern.test("user@")); // false

// Match and extract
const result = "user@example.com".match(pattern);

import re

pattern = r"^[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}$"
flags = re.IGNORECASE

# Test a string
if re.fullmatch(pattern, "user@example.com", flags):
    print("Valid")

# Find all matches in text
matches = re.findall(pattern, text, flags)

import java.util.regex.*;

String pattern = "^[a-zA-Z0-9._%+\\-]+@[a-zA-Z0-9.\\-]+\\.[a-zA-Z]{2,}$";
Pattern p = Pattern.compile(pattern, Pattern.CASE_INSENSITIVE);

Matcher m = p.matcher("user@example.com");
boolean isValid = m.matches(); // true

// Find occurrences
Matcher finder = p.matcher(inputText);
while (finder.find()) {
    System.out.println(finder.group());
}