Array Deduplication

Code

function unique(arr) {
  return [...new Set(arr)];
}

// Deduplicate object array by specified field
function uniqueBy(arr, key) {
  const seen = new Set();
  return arr.filter(item => {
    const val = item[key];
    if (seen.has(val)) return false;
    seen.add(val);
    return true;
  });
}

Explanation

Leverages Set's element uniqueness for fast deduplication; object arrays can be deduplicated by a specified field.

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