如何去掉javascript中的重复项？

const arr = [1, 2, 2, 3, 4, 4, 5];
const uniqueArr = [...new Set(arr)];
console.log(uniqueArr); // [1, 2, 3, 4, 5]

const arr = [1, 2, 2, 3, 4, 4, 5];
const uniqueArr = arr.filter((value, index, self) => {
  return self.indexOf(value) === index;
});
console.log(uniqueArr); // [1, 2, 3, 4, 5]

const arr = [1, 2, 2, 3, 4, 4, 5];
const uniqueArr = arr.reduce((prev, curr) => {
  if (!prev.includes(curr)) {
    prev.push(curr);
  }
  return prev;
}, []);
console.log(uniqueArr); // [1, 2, 3, 4, 5]

const arr = [1, 2, 2, 3, 4, 4, 5];
const uniqueArr = [];
arr.forEach((value) => {
  if (uniqueArr.indexOf(value) === -1) {
    uniqueArr.push(value);
  }
});
console.log(uniqueArr); // [1, 2, 3, 4, 5]