Happy Number LeetCode solution in JavaScript

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var isHappy = function (n) {
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  if (n < 10) {
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    if (n === 1 || n === 7) {
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      return true;
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    }
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    return false;
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  }
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  let total = 0;
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  while (n > 0) {
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    let sq = n % 10;
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    total += sq ** 2;
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    n -= sq;
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    n /= 10;
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  }
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  if (total === 1) {
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    return true;
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  }
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  return isHappy(total);
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};