jQuery & JavaScript

Split a string into an array in JavaScript (with jQuery helpers)

jQuery & JavaScript · By the Postback Notes editorial team · Published 2026-08-11

jQuery has no split function of its own: split is a method of every JavaScript string. jQuery helps with what comes after, such as iterating with $.each, but splitting is plain JavaScript and works the same with or without the library.

Basics

"red,green,blue".split(",");          // ["red", "green", "blue"]
"red,green,blue".split(",", 2);       // ["red", "green"]  (limit)
"abc".split("");                      // ["a", "b", "c"]
"no separator".split(",");            // ["no separator"]
"".split(",");                        // [""]  (one empty string, not an empty array)

Real input is messy

Users type "sql, jquery , css,,". Clean it in one pass:

function toList(text) {
  return text.split(",")
             .map(function (s) { return s.trim(); })
             .filter(function (s) { return s !== ""; });
}
toList("sql, jquery ,  css,,");        // ["sql", "jquery", "css"]

// several possible separators: comma, semicolon or new line
"a; b\nc,d".split(/[;,\n]+/).map(s => s.trim());  // ["a", "b", "c", "d"]

A regular expression separator accepts alternatives and repeated separators at once. If the regular expression contains capturing parentheses, the captured separators are included in the result, which is rarely wanted; use (?:…) groups.

With values from ASP.NET controls

<asp:TextBox ID="txtTags" runat="server" placeholder="e.g. sql, jquery, css" />
<ul id="tagPreview"></ul>
<script>
  $(function () {
    $("#<%= txtTags.ClientID %>").on("input", function () {
      var $list = $("#tagPreview").empty();
      $.each(toList($(this).val()), function (i, tag) {
        $("<li>").text(tag).appendTo($list);   // .text() keeps user input as text
      });
    });
  });
</script>

$.each(array, function (index, value) { … }) passes the index first, unlike the native forEach(function (value, index) { … }). Building elements with .text() avoids injecting HTML from the user's input.

Splitting on the server too

The posted text box value must be split and validated again in C#:

string[] tags = txtTags.Text
    .Split(new[] { ',', ';', '\n' }, StringSplitOptions.RemoveEmptyEntries)
    .Select(t => t.Trim())
    .Where(t => t.Length > 0 && t.Length <= 30)
    .Distinct(StringComparer.OrdinalIgnoreCase)
    .Take(10)
    .ToArray();

On .NET 5 and later, StringSplitOptions.TrimEntries trims at the same time. Splitting a date into its parts is a special case that deserves parsing instead: Split a date into day, month and year.

Common mistakes

Official documentation