First Missing Positive LeetCode solution in JavaScript

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/**
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 * @param {number[]} nums
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 * @return {number}
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 */
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var firstMissingPositive = function (nums) {
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  //first make all negative numbers to zero =>zero means we ignore whis number
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  for (let index = 0; index < nums.length; index++) {
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    if (nums[index] < 0) nums[index] = 0;
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  }
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  for (let index = 0; index < nums.length; index++) {
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    const temp = Math.abs(nums[index]);
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    const element = temp - 1;
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    if (element < nums.length && element >= 0)
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      nums[element] =
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        nums[element] === 0 ? -(nums.length + 1) : Math.abs(nums[element]) * -1;
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  }
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  for (let index = 0; index < nums.length; index++) {
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    const element = nums[index];
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    if (element >= 0) return index + 1;
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  }
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  return nums.length + 1;
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};