JS implements array deduplication algorithm

This time I will bring you JS to implement the array deduplication algorithm. What are theprecautions for JS to implement the array deduplication algorithm?. Here is a practical case, let’s take a look.

Test case:

arr = ["1",3,"1",1,4,5,1,"2",5,1,{"name ":"li","age":20},2,4,3,{"name":"li","age":20},""];

Method 1: With the help of temporary array and indexOf,The algorithm complexity is:O(n^2)

function unique1(arr){ var temp = []; for(var i=0; i
        

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Test result:

unique1(arr): ["1", 3, 1, 4, 5, "2", Object { name="li", age=20}, 2, Object { name="li", age=20}, ""]

bug Unable to distinguish objects

Method 2: UseObject objectinJavaScriptas Ha Greek table

function unique2(arr){ var temp=[]; var hash={}; for(var i=0; i
        

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Test result:

unique2(arr): ["1", 3, 4, 5, "2", Object { name="li ", age=20}, ""]

bug: Unable to distinguish: 1 and "1"

Modification

function unique2(arr){ var temp=[]; var hash={}; for(var i=0; i
        

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Test result:

unique2(arr): ["1", 3, 1, 4, 5, "2", Object { name="li", age=20}, 2, ""]

Method 3: First use sort to sort thearray, and then use a temporary array to store the last one of the same element. This method can only be used for pure Number type arrays

function unique3(arr){ arr.sort(function(a,b){ return a-b; }); var temp = []; for(var i=0;i
        

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I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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