telephone-number-validator.html

<!DOCTYPE html>
<html>
<body>


<script>
    //https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/javascript-algorithms-and-data-structures-projects/telephone-number-validator
    //Return true if the passed string looks like a valid US phone number.


    function telephoneCheck(str) {
        const regexp2 = /^(1\s?)?(\(\d{3}\)|\d{3})[\s\-]?\d{3}[\s\-]?\d{4}$/;
        return regexp2.test(str); 
}
//tests 
console.log(telephoneCheck("555-555-5555"));
console.log(telephoneCheck("1 555-555-5555"));
console.log(telephoneCheck("1 (555) 555-5555"));
console.log(telephoneCheck("5555555555"));
console.log(telephoneCheck("(555)555-5555"));
console.log(telephoneCheck("1(555)555-5555"));
console.log(telephoneCheck("555-5555"));
console.log(telephoneCheck("5555555"));
console.log(telephoneCheck("1 555)555-5555"));
console.log(telephoneCheck("1 555 555 555"));
console.log(telephoneCheck("(6054756961)"));
console.log(telephoneCheck("2 (757) 622-7382"));
console.log(telephoneCheck("0 (757) 622-7382"));
console.log(telephoneCheck("-1 (757) 622-7382"));
console.log(telephoneCheck("10 (757) 622-7382"));
console.log(telephoneCheck("27576227382"));
console.log(telephoneCheck("555)-555-5555"));
console.log(telephoneCheck("(555-555-5555"));
console.log(telephoneCheck("(555)5(55?)-5555"));


</script>


</body>
</html>