js 编程题

// 方法一：使用循环和条件判断
function removeDuplicatesWithLoop(arr) {
  let uniqueArray = [];
  for (let i = 0; i < arr.length; i++) {
    if (uniqueArray.indexOf(arr[i]) === -1) {
      uniqueArray.push(arr[i]);
    }
  }
  return uniqueArray;
}

// 方法二：使用数组的filter方法
function removeDuplicatesWithFilter(arr) {
  return arr.filter((item, index) => arr.indexOf(item) === index);
}

// 方法三：使用ES6的Set对象
function removeDuplicatesWithSet(arr) {
  return [...new Set(arr)];
}

// 测试数组
const arrayWithDuplicates = [1, 2, 2, 3, 4, 4, 5];

console.log(removeDuplicatesWithLoop(arrayWithDuplicates)); // 输出: [1, 2, 3, 4, 5]
console.log(removeDuplicatesWithFilter(arrayWithDuplicates)); // 输出: [1, 2, 3, 4, 5]
console.log(removeDuplicatesWithSet(arrayWithDuplicates)); // 输出: [1, 2, 3, 4, 5]