Island Perimeter LeetCode solution in JavaScript

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var islandPerimeter = function (grid) {
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  let perimeter = 0;
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  let row = grid.length;
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  let col = grid[0].length;
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  for (let i = 0; i < grid.length; i++) {
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    for (let j = 0; j < grid[i].length; j++) {
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      if (grid[i][j] === 1) {
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        if (i === 0 || (i > 0 && grid[i - 1][j] === 0)) perimeter++;
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        if (i === row - 1 || (i < row - 1 && grid[i + 1][j] === 0)) perimeter++;
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        if (j === 0 || (j > 0 && grid[i][j - 1] === 0)) perimeter++;
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        if (j === col - 1 || (j < col && grid[i][j + 1] === 0)) perimeter++;
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      }
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    }
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  }
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  return perimeter;
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};