JavaScript Little Exercise 3

Take out the elements of the common part of array 1 and array 2

Thought 1: Put the array 1 into the map, and then iterate over the array 2, the elements in arrays 2 do not exist in the map does not work, if the element in the array 2 already exists in the map, push it into a new array newarr, and finally return the new array.

function Getsamenums (ARR1,ARR2) {    var mp={};    var newarr=[];    for (Var i=0;i<arr1.length;i++) {        if (!mp[arr1[i]) {            mp[arr1[i]]=1;        }    }    for (Var i=0;i<arr2.length;i++) {        if (Mp[arr2[i]) {            newarr.push (arr2[i]);}    }    return NEWARR;} var arr1 = [4,2,1,10,5];var arr2 = [2,3,4,0,10,5];console.log (Getsamenums (ARR1,ARR2)];

Thought 2: Sort the array 1, array 2 in ascending order, and then iterate from the beginning, comparing. If equal, the element is push into a new array, and if the element in array 1 is larger than the element in array 2, the element in the array 1 is compared to the next element in array 2, and if the element in array 1 is less than that element in array 2, Compares the next element in the array 1 with the element in array 2

    var arr = [];    Arr1.sort (sortby);    Arr2.sort (sortby);    var i=0;
    var j=0;    while (I<arr1.length && J < arr2.length) {        if (arr1[i] = = Arr2[j]) {            arr.push (arr1[i]);            i++;
            j + +;        } else if (Arr1[i]>arr2[j]) {            j + +;        } else{            i++;        }    }    return arr;} var arr1 = [4,2,1,10,5];var arr2 = [2,3,4,0,10,5];console.log (Getsamenums (ARR1,ARR2)];

Thought 3: Sort the array 1 in ascending order, define a new global array, and then iterate over the array 2, using the binary lookup to determine whether the element in array 2 is in array 1, does not operate, then push it into a new array, and finally return. Call the method, and then print out the new array.

function SortBy (A, b) {return a-a    ;} var newArr = [];
function BinarySearch (arr,findval,leftindex,rightindex) {    if (leftindex>rightindex) {        return;    }    var Midindex=math.floor ((Leftindex+rightindex)/2);    var midval=arr[midindex];    if (midval>findval) {        binarysearch (arr,findval,leftindex,midindex-1);    } else if (midval<findval) {        binarysearch (arr,findval,midindex+1,rightindex);    } else{        Newarr.push (findval)        return;}    } function Getsamenums (ARR1,ARR2) {    arr1.sort (sortby);    for (Var i=0;i<arr2.length;i++) {       binarysearch (arr1,arr2[i],0,arr1.length-1);    }} var arr1 = [4,2,1,10,5];var arr2 = [2,3,4,0,10,5];getsamenums (ARR1,ARR2); Console.log (NEWARR);

JavaScript Little Exercise 3