Using JavaScript for Array de-weight-an efficient algorithm

Recently busy, no time to update the blog, and so busy will be finishing an article using Angularjs to build a medium-sized single-page application (SPA) articles, look forward to! Occupy a hole first.

There are many kinds of algorithms for array de-weight, the following is one.

Ideas are as follows:

1. Defines an empty object, obj;
2. Loop array arr, determine if Obj[arr[i]] is false, and if so, place the array element in result and set Obj[arr[i]] to true;
3. Obj[arr[0]] "must be false, because obj is empty, arr[0] will be placed in result, and Obj[arr[0]] is set to true;
4. In the process of looping, if any element (such as nth Element) and Arr[0] is the same, then Obj[arr[n]] will be the same as obj[arr[0]] (all true), because key is the same, value must be the same.

So we can go to the heavy.

The code is as follows:

1 functionUnique (arr) {2     varobj={};3     varresult=[];4      for(vari=0;i<arr.length;i++){5         if(!Obj[arr[i]]) {6 Result.push (Arr[i]);7obj[arr[i]]=true;8         }9     }Ten     returnresult; One } A varArray = [32,12,4,27,12,9,20,32,12,8,44,18]; -Console.log (unique (array));

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After writing, we found that there is a simpler array de-RE algorithm, using the array filter method, the following is the code:

1 function () {2     return this. Filter (function  (V, I, m) {3         return i <= m.indexof (v ); 4     }); 5 }; 6 var array = [1,2,3,12,3,2,1,2,30]; 7 array.unique ();

Using JavaScript for Array de-weight-an efficient algorithm