What is wrong with my REGEX look ahead

1

Hey guys,
The main problem I am having is trying to close the set of parenthesis. This problems is from the advances algorithm challenges. I have implemented a look ahead but for some reason it still does not match the first instance of the the parenthesis. Can you Help me out?


^(([1]{1}))?\s?\((?=[0-9]{3})\)?\s?[-]?([0-9]{3})[-]?\s?([0-9]{4})$

The following parameter is coming up as false when passed into my function

(555-555-5555

down below is what I have implemented without the look ahead .

function telephoneCheck(str) {
  
  var checkagainst = /^([1]{1})?\s?\(?([0-9]{3})\)?\s?[-]?([0-9]{3})[-]?\s?([0-9]{4})$/g;
  if (checkagainst.test(str)) {
    return(true);
  } else {
    return(false);
  }
  
  }

telephoneCheck("(275)76227382");