The intersection of multiple arrays needs to be achieved in the project, so this example applies only to specific scenarios. For example, a array of var a = {1000,10001,10002,10003}; b array var b = {10002, 10003}; C array var c = {10003}; You need to get an array of intersections of these three arrays.
The idea is as follows: first, a minimum array is an array of a, and the smallest number of elements is also the length of the array A. Then iterate over each array, get the shortest length of these array lengths, and get the shortest length array. The iteration's smallest array is then compared to the array, and the element is equal, using a counter to determine whether the element exists in each array as an intersection element.
The idea is relatively simple, but you can achieve the intersection of most groups, the code is as follows:
Copy Code code as follows:
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 transitional//en" >
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<meta name= "generator" content= "EditPlus" >
<meta name= "Author" content= "" >
<meta name= "Keywords" content= "" >
<meta name= "Description" content= "" >
<script>
function GetValues (obj) {
var values = "";
var L = obj.options.length;
for (var i=0; i<l; i++) {
if (I!= (l-1)) {
Values + + obj.options (i). Value + "_";
}
else {
Values + = Obj.options (i). value;
}
}
return values;
}
function _test () {
var ids = getValues (DOCUMENT.ALL.AA);
var AA = _getintersection (IDS);
}
function _getintersection (SRC) {
var tary = Src.split ("_");
Smallest array
var minary = null;
var min = tary[0].split (","). Length; Initializes the first array of the smallest length
Minary = Tary[0].split (",");
for (var i = 1, len = tary.length; i<len; i++) {
var temp = Tary[i].split (",");
if (Temp.length < min) {
min = temp.length;
Minary = temp;
}
}
Alert ("Smallest array:" +minary);
var ret = ';
for (var i = 0, len = minary.length; i<len; i++) {
var srcnum = parseint (Minary[i]);
var counter = 0;
for (var j = 0, LL = tary.length j<ll; J + +) {
var tt = Tary[j].split (",");
for (var k = 0, L = tt.length k<l; k++) {
var tarnum = parseint (Tt[k]);
if (Srcnum = = Tarnum) {
Counter + +;
}
}
}
if (counter = = Tary.length) {
RET + + Srcnum + ",";
}
}
ret = Strslice (ret, ', ');
Alert ("Intersection is:" + ret);
}
Remove End Separator
function Strslice (str, split) {
if ((Str!=null && str!= "") && (split!= '))
Return ((Str.charat (str.length-1) = Split)? str.substring (0, str.length-1): STR);
Else
return str;
}
</script>
</HEAD>
<BODY>
<button onclick= "javascript:_test ();" > Testing </button>
<select name= "AA" id= "AA" size= "6" multiple>
<option value= "10004,10005,10008,10009,10010,10018" > Test 1</option>
<option value= "10004,10005,10006,10008,10009,10010,10018" > Test 2</option>
<option value= "10004,10005,10006,10008,10009,10010,10018" > Test 3</option>
<option value= "10004,10006,10008" > Test 4</option>
<option value= "10004,10010,10018" > Test 5</option>
</select>
</BODY>
</HTML>
