js the number of computing elements in the array occurs, and to achieve deduplication

function getCount (ARR, Rank, ranktype) { 
     var obj = {}, K, of arr1 = [];
     for ( var I = 0, len = arr.length; I <len; I ++ ) { 
        K = ARR [I];
         IF (obj [K]) 
            obj [K] ++ ;
         the else  
            obj [K] =. 1 ; 
    } 
    // save the results {el- 'element', count- occurrences} 
    for ( var O in obj) { 
        arr1.push ({EL: O, COUNT: obj [O]}); 
    } 
    // (descending) 
    arr1.sort ( function(N1, N2) {
         return n2.count - n1.count 
    }); 
    // if ranktype 1, for the ascending order, the array inverted 
    IF (ranktype === 1 ) { 
        of arr1 = arr1.reverse (); 
    } 
    var Rank = || Rank1 arr1.length;
     return arr1.slice (0 , Rank1); 
} 

getCount ([ 1,2,3,1,2,5,2,4,1,2,6,2,1,3 , 2]) // default, returns the number of all the elements appear 
getCount ([1,2,3,1,2,5,2,4,1,2,6,2,1,3,2], 3 ) // parameter passing (rank = 3), only returns three occurrences of sorting 
getCount ([1,2,3,1,2,5,2,4,1,2,6,2,1,3, 2], null ,. 1) // parameter passing (ranktype = 1, rank = null ), returns all elements of the number of occurrences in ascending
getCount ([1,2,3,1,2,5,2,4,1,2,6,2,1,3,2], 3,1) // transmission parameters (rank = 3, ranktype = 1 ), only returns the number of the sort appears (in ascending order) in the first three