7, array de-weight and sorting

First, the array to weight

    /** * Array de-weight * 1, double cycle method-determine if there is an equal item * Note: The second loop starts with i+1 **/Let circlerepeat=function (ary) { for(Let i=0; i<ary.length;i++) {Let cur=Ary[i];  for(Let j=i+1; j<ary.length;j++){                if(cur = = =Ary[j]) {Ary.splice (J,1); J--; }            }        }        returnary};//Console.log (Circlerepeat ([1,2,3,4,1,1,2,2,3,4,4]));    /** * Array de-weight * 2, new array method-new array No current item-put new array * Note: indexOf usage **/Let newarrrepeat=function (ary) {Let Ary2= [];  for(Let i=0; i<ary.length;i++) {Let cur=Ary[i]; if(Ary2.indexof (cur) = = =-1) {ary2.push (cur); }        }        returnAry2};//Console.log (Newarrrepeat ([1,2,3,4,1,1,2,2,3,4,4]));    /** * Array de-weight * 3, sort order-determine if two adjacent items are equal after sorting * Note: Sort usage and prevent array collapse **/Let sortrepeat=function (ary) {Ary.sort (A, b) {returnA-C;        });  for(Let i=0; i<ary.length;i++){            if(Ary[i] = = = ary[i+1]) {Ary.splice (I,1); I--;//Prevent array collapse            }        }        returnary; };//Console.log (Sortrepeat ([1,2,3,4,1,1,2,2,3,4,4]));    /** * Array deduplication * 4, object Method-to see if there are duplicates in the object, if any, delete the array the item * Note: The object's property name and property value **/Let objrepeat=function (ary) {Let obj={};  for(Let i=0; i<ary.length; i++) {Let cur=Ary[i]; if(obj[cur]==cur) {Ary.splice (i,1); I--; } Obj[cur]=cur; }        returnary; };//Console.log (Objrepeat ([1,2,3,4,1,1,2,2,3,4,4]));    /** * Array de-weight * 5, the object does not duplicate the name of the property-the use of the object does not duplicate the attribute can not only go to the weight-property names; and the property value also records the number of occurrences of the current element * Note: object's property name and property value **/Let objnamerepeat=function (ary) {Let obj={},ary2=[];  for(Let i=0; i<ary.length; i++) {Let cur=Ary[i]; /*if (Obj[cur]) {obj[cur]++;             Continue } obj[cur]=1; Adds the contents of the array to the object and assigns a value of 1;*/            if(Obj[cur]) {Obj[cur]++; }Else{Obj[cur]=1; }        }        returnobj; };//Console.log (Objnamerepeat ([1,2,3,4,1,1,2,2,3,4,4]));

Second, array sorting

    /** * Quick Sort * 1, find middle position and corresponding value * 2, each item in the array is compared with the median value left[] right[] * 3, recursive + array concatenation **/Let quickSort=function (ary) {if(ary.length<=1){            returnary} let num= Math.floor (ary.length/2); Let NumValue= Ary.splice (num,1)[0]; Let left= [],right = [];  for(Let i=0; i<ary.length;i++) {Let cur=Ary[i]; if(cur<NumValue) {Left.push (cur)}Else{right.push (cur)}}returnQuickSort (left). Concat ([Numvalue],quicksort (right))};//Console.log (QuickSort ([2,43,7,89,0,6,4,2,5,6]))    /** * Insert sort * 1, take the corresponding value of the first array to compare.     * 2, the loop original array and the left array * 3, the original array the current item is less than each item in leave, put it to the front.     * 4. The current item of the original array is greater than one of the items in left and is placed after this item. * 5, return to left **/Let insertsort=function (ary) { let left= Ary.splice (0,1);  for(Let i=0; i<ary.length;i++) {Let cur=Ary[i];  for(Let j=left.length-1; j>=0;){                if(cur<Left[j]) {J--; if(j = =-1) {left.unshift (cur); }                }Else{Left.splice (J+1,0, cur);  Break; }            }        }        returnLeft };//Console.log (Insertsort ([2,43,7,89,0,6,4,2,5,6]))    /** * Bubble sort * 1, the first loop--the length of the array = Compare the number of wheels Ary.length * 2, the second loop--the number of times per round comparison ary.length-1-i (last item not compared) * 3, each The second comparison puts the larger value back-and each wheel compares the maximum value to the last * 4, returning the array **/Let bubblesort=function (ary) { for(Let i=0; i<ary.length;i++){             for(Let j=0; j<ary.length-1-i;j++){                if(ary[j]>ary[j+1]) {Let TMP= ary[j+1]; Ary[j+1] =Ary[j]; ARY[J]=tmp; }            }        }        returnary};//Console.log (Bubblesort ([2,43,7,89,0,6,4,2,5,6]));

7, array de-weight and sorting