Delete duplicate elements from an array

Question

For example  I have an array like this   var arr    1  2  2  3  4  5  5  5  6  7  7  8  9  10  10    My purpose is to discard repeating elements from array and get final array like this   var arr    1  2  3  4  5  6  7  8  9  10    How can this be achieved in JavaScript   NOTE  array is not sorted  values can be arbitrary order

User · Answer

you may try like this using jquery   var arr    1 2 2 3 4 5 5 5 6 7 7 8 9 10 10       var uniqueVals             each arr  function i  el           if   inArray el  uniqueVals      -1  uniqueVals push el

User · Answer

As elements are yet ordered  you don t have to build a map  there s a fast solution    var newarr    arr 0    for  var i 1  i lt arr length  i         if  arr i   arr i-1   newarr push arr i        If your array weren t sorted  you would use a map    var newarr    function arr     var m       newarr        for  var i 0  i lt arr length  i          var v   arr i       if   m v           newarr push v         m v  true              return newarr     arr     Note that this is  by far  much faster than the accepted answer

User · Answer

Try following from Removing duplicates from an Array simple    Array prototype removeDuplicates   function       var temp new Array      this sort      for i 0 i lt this length i         if this i   this i 1    continue      temp temp length  this i         return temp       Edit    This code doesn t need sort    Array prototype removeDuplicates   function       var temp new Array      label for i 0 i lt this length i             for var j 0  j lt temp length j       check duplicates             if temp j   this i    skip if already present                 continue label                          temp temp length    this i         return temp         But not a tested code

User · Answer

var arr    1 2 2 3 4 5 5 5 6 7 7 8 9 10 10    function squash arr       var tmp           for var i   0  i  lt  arr length  i             if tmp indexOf arr i      -1           tmp push arr i                        return tmp     console log squash arr      Working Example http   jsfiddle net 7Utn7   Compatibility for indexOf on old browsers

User · Answer

It s easier using Array filter   var unique   arr filter function elem  index  self        return index     self indexOf elem

[javascript] Delete duplicate elements from an array

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