Using the method of reduce to implement object array de-weight

In the development and interview, the problem of array de-weight is often favored by the beloved, the shortest code to solve the problem will make the efficiency of a greater increase. Normal array, we can use the filter method to go to the weight, details see my blog: http://www.cnblogs.com/mmykdbc/p/8422419.html

When it is an array of objects, filter is dwarfed, and then with that kind of stupid one traversal method will make the work efficiency greatly reduced, this time, need to use the reduce overlay method, the code:

  Let arr = [{' All ': 1}, {' All ': 2}, {' All ': 3}, {' All ': 4}, {"All": 1}];  Let hash = {};  arr = Arr.reduce (item, Next) = {    Hash[next.all]? "": hash[next.all] = True && Item.push (next);    Return item  }, []);  Console.log (arr);

Results:

Using the method of reduce to implement object array de-weight