在JavaScript中按逗号分隔的字符串分割值

Question

Here is my issue:

I have RadListBox and I'm trying to get the values and append them so the result would be displayed like that: '1,2,3,4' but I'm getting back : 1,2,3,4, Does anyone know how can I achieve that?

Problem starts here:

var sbLocationsIDS = new StringBuilder();
             for (i = 0; i < LocationIDS.get_items().get_count(); i++) {
                 sbLocationsIDS.append(LocationIDS.getItem(i).get_value()+ ",");  
             }

The result: sbLocationsIDS =1,2,3,4, instead of '1,2,3,4'

The Rest of the Code:

 function openNewTab(url) {
         var captureURL = url;
         var win = window.open(captureURL, '_blank');
         win.focus();
     }

     function GetComparisonsReport(sender, args) {
         var isValid = Page_ClientValidate('validateComparisons');
         if (isValid) { // If its true is going to fire the rest of the code
             var SessionID = getUrlVars()["SessionID"];
             var companyCodeVal = document.getElementById("<%=hfC.ClientID%>").value;
             var LocationIDS = $find("<%=rlbSelectedLocation.ClientID %>");
             var CategoriesIDS = $find("<%=rlbSelectedCategory.ClientID %>");
             var fileType = $find("<%=rcbFileType.ClientID %>");
             var fromFirstPeriod = $find("<%=rdpFromFirstPeriod.ClientID %>");
             var toFirstPeriod = $find("<%=rdpToFirstPeriod.ClientID %>");
             var fromSecondPeriod = $find("<%=rdpFromSecondPeriod.ClientID %>");
             var toSecondPeriod = $find("<%=rdpToSecondPeriod.ClientID %>");;
              if (LocationIDS.get_items().get_count() < 0) {
                 radalert("Please choose locations and select the Add button.<h3 style='color: #ff0000;'></h3>", 420, 170, "Case Global Alert");
                 return;
             }
             if (CategoriesIDS.get_items().get_count() < 0) {
                 radalert("Please choose categories and select the Add button.<h3 style='color: #ff0000;'></h3>", 420, 170, "Case Global Alert");
                 return;
             }
             var fromFirstPeriodDateValSelected = fromFirstPeriod.get_dateInput().get_selectedDate().format("yyyy/MM/dd");
             var toFirstPeriodDateValSelected = toFirstPeriod.get_dateInput().get_selectedDate().format("yyyy/MM/dd");
             var fromSecondPeriodDateValSelected = fromSecondPeriod.get_dateInput().get_selectedDate().format("yyyy/MM/dd");
             var toSecondPeriodDateValSelected = toSecondPeriod.get_dateInput().get_selectedDate().format("yyyy/MM/dd");
             var fileTypeValSelected = fileType.get_selectedItem().get_value();


             var sbLocationsIDS = new StringBuilder();
             for (i = 0; i < LocationIDS.get_items().get_count(); i++) {
                 sbLocationsIDS.append(LocationIDS.getItem(i).get_value()+ ",");  // The problem is here!!!
             }
             var sbCategoriesIDS = new StringBuilder();
             for (i = 0; i < CategoriesIDS.get_items().get_count(); i++) {
                 sbCategoriesIDS.append(CategoriesIDS.getItem(i).get_value() + ",");
             }
             var ComparisonsURL = (String.format("https://www.test.com/cgis/{0}/reports/ConnectTorptIncidentsCountByLocationInterval.asp?SessionID={1}&locString={2}&catString={3}&FromDate1={4}&&ToDate1={5}&FromDate2={6}&ToDate2={7}&ExportType={8}", companyCodeVal, SessionID, sbLocationsIDS, sbCategoriesIDS, fromFirstPeriodDateValSelected, toFirstPeriodDateValSelected, fromSecondPeriodDateValSelected, toSecondPeriodDateValSelected, fileTypeValSelected));
             openNewTab(ComparisonsURL);
         }
     }

     String.format = function () {
         // The string containing the format items (e.g. "{0}")
         // will and always has to be the first argument.
         var theString = arguments[0];
         // start with the second argument (i = 1)
         for (var i = 1; i < arguments.length; i++) {
             // "gm" = RegEx options for Global search (more than one instance)
             // and for Multiline search
             var regEx = new RegExp("\\{" + (i - 1) + "\\}", "gm");
             theString = theString.replace(regEx, arguments[i]);
         }
         return theString;
     }

     function getUrlVars() {
         var vars = {};
         var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function (m, key, value) {
             vars[key] = value;
         });
         return vars;
     }

     // Initializes a new instance of the StringBuilder class
     // and appends the given value if supplied
     function StringBuilder(value) {
         this.strings = new Array("");
         this.append(value);
     }

     // Appends the given value to the end of this instance.
     StringBuilder.prototype.append = function (value) {
         if (value) {
             this.strings.push(value);
         }
     }

     // Clears the string buffer
     StringBuilder.prototype.clear = function () {
         this.strings.length = 1;
     }

     // Converts this instance to a String.
     StringBuilder.prototype.toString = function () {
         return this.strings.join("");
     }

Answer 1

The problem is your loop is appending , always even for the last item in the loop.

You want to append only for all items other than the last. There are multiple ways to do that, simplest being: check if the current element is the last and if so, do not append ,

    var sbLocationsIDS = new StringBuilder();
    for (i = 0; i < LocationIDS.get_items().get_count(); i++) {
        sbLocationsIDS.append(LocationIDS.getItem(i).get_value()); //append only value
        if(i != (LocationIDS.get_items().get_count() -1)) { //if not last item in list
            sbLocationsIDS.append(","); //append ,
        }
    }

There are other ways to do it, and depending on what you want to do with the values in the future, these may be pretty useful. (I see that the append in your code is actually a call to join , so this is actually a simpler version)

Add the values of the list to a array and use Array.join :

var select = document.getElementById("locationId");
var options = select.options;
var optionsArray = [];
if(options) {
    for (var i=0; i<=options.length; i++) {
        //text is the text displayed in the dropdown. 
        //You can also use value which is from the value attribute of >option>
        optionsArray.push(options[i].text);  
    }
}
var sbLocationsIDS = optionsArray.join(",");

With JQuery, the above code becomes a bit more simple:

var optionsArray = [];
$("#locationId option").each(function(){
    optionsArray.push(options[i].text);
});
var sbLocationsIDS = optionsArray.join(",");

Actually, if you decide yo use JQuery, you can use jquery.map : (idea from Assigning select list values to array )

 $(document).ready(function() { $("#b").click(function() { var sbLocationsIDS = jQuery.map($("#locationId option"), function(n, i) { return (n.value); }).join(","); alert(sbLocationsIDS); }); }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <select id="locationId"> <option value="1">1</option> <option value="2">2</option> <option value="3">3</option> </select> <button id="b">Click</button>