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/**
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 * @param {string} s
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 * @return {number}
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 */
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var secondHighest = function (s) {
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  //let's start by getting rid of all the non-digits
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  let myRegex = /\D/g;
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  s = s.replace(myRegex, "");
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  var digits = s.split("");
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  //at this point, digits is an array of all the digit characters that were originally in s
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  digits.sort(function (a, b) {
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    return b - a;
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  }); //sort the array into descending order
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  var res = new Set(digits); //turn the array into a set, to remove duplicates
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  if (res.size <= 1) {
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    //if the set is sized 1, then there is no second largest digit
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    return -1;
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  } else {
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    //otherwise, the second largest digit would be at index 1 (because we sorted the array into descending order)
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    return [...res][1];
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  }
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};