Using RegExp in JS

regexp.js

//RegExp for URL validation - ^(?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~:/?#[\]@!\$&'\(\)\*\+,;=.]+$
let exp = ^(?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~:/?#[\]@!\$&'\(\)\*\+,;=.]+$;
function testInfo(phoneInput) {  
  var OK = exp.exec(phoneInput.value);  
  if (!OK)  
    window.alert(phoneInput.value + ' isn\'t a phone number with area code!');  
  else
    window.alert('Thanks, your phone number is ' + OK[0]);  
}