Merging of arrays, de-weight, sorting

One, the combined de-weight of two arrays:

vararr1 = [' A ', ' B '];varARR2 = [' A ', ' C ', ' d '];varARR3 = [1, ' d ', undefined,true,NULL];//merge two arrays, go to heavyvarConcat_ =function(ARR1,ARR2) {//do not directly use the var arr = arr1, so that arr is only a reference to ARR1, and the modifications of both will affect each other    vararr =Arr1.concat (); //or use slice () to copy, var arr = arr1.slice (0)     for(vari=0;i<arr2.length;i++) {arr.indexof (arr2[i])= = =-1? Arr.push (Arr2[i]): 0; }    returnarr;}   Console.log (Concat_ (ARR1,ARR2)); //[' A ', ' B ', ' C ', ' d ']

Two, the merging of multiple arrays to remove weight:

vararr1 = [' A ', ' B '];varARR2 = [' A ', ' C ', ' d '];varARR3 = [1, ' d ', undefined,true,NULL];//merge multiple arrays, go to heavyvarConcat_ =function(ARR1,ARR2,ARR3) {if(Arguments.length <= 1){        return false; }    varConcat_ =function(ARR1,ARR2) {vararr =Arr1.concat ();  for(vari=0;i<arr2.length;i++) {arr.indexof (arr2[i])= = =-1? Arr.push (Arr2[i]): 0; }        returnarr; }    varresult =Concat_ (ARR1,ARR2);  for(vari=2;i<arguments.length;i++) {result=Concat_ (Result,arguments[i]); }    returnresult;} Console.log (Concat_ (ARR1,ARR2,ARR3));//["A", "B", "C", "D", 1, undefined, true, NULL]

Three, multiple arrays merged, de-heavy, sort:

//merge multiple arrays, go to heavy, sortvarARR1 = [1,6,4,0];varARR2 = [8,20,7,4.5];varARR3 = [6,0,7,90,2];varConcat_ =function(ARR1,ARR2,ARR3) {if(Arguments.length <= 1){        return false; }    varConcat_ =function(ARR1,ARR2) {vararr =Arr1.concat ();  for(vari=0;i<arr2.length;i++) {arr.indexof (arr2[i])= = =-1? Arr.push (Arr2[i]): 0; }        returnarr; }    varresult =Concat_ (ARR1,ARR2);  for(vari=2;i<arguments.length;i++) {result=Concat_ (Result,arguments[i]); }    //Sort    functionSortnumber (A, b) {returnAb; }    returnResult.sort (sortnumber);} Console.log (Concat_ (ARR1,ARR2,ARR3))//[0, 1, 2, 4, 4.5, 6, 7, 8, +--]

Reference:

http://m.blog.csdn.net/article/details?id=49634041

Merging of arrays, de-weight, sorting