简单一维数组去重

set 方法

 let arr = [1,0,0,2,9,8,3,1];

    function unique(arr) {
         return Array.from(new Set(arr))
      }
     console.log(unique(arr));   // [1,0,2,9,8,3]
  or
console.log(...new Set(arr)); // [1,0,2,9,8,3]

数组中对象去重

let newArr = [];
    let obj = {};
    for (var i = 0; i < arr.length; i++) {
      if (!obj[arr[i].key]) {
        newArr.push(arr[i]);
        obj[arr[i].key] = true;
      }
    }
    console.log(newArr);