.selector?.selector was a String on a jQuery collection: the CSS selector passed to jQuery() when the set was created. Example: $("div.item").selector → "div.item". It was never reliable after traversal (.find(), .eq(), …). Prefer keeping your own selector variable or the official plugin parameter pattern.
// jQuery 1.x / 2.x only
$("div.item").selector // "div.item"
// After traversal — do not trust it to re-query the same set
$("div.item").eq(0).selector // still "div.item", but length is 1
// jQuery 3.x
$("div.item").selector // undefined (removed)
// Modern plugin pattern (official)
$.fn.foo = function (selector, options) { /* … */ };
$("div.bar").foo("div.bar", { dog: "bark" });.selector (Legacy)Only for understanding older code or Migrate warnings — not for new features.
$("div.item").$set.selector..eq(), .filter(), or .add().selector as a method argument instead.undefined — keep your own variable.| Piece | Required? | Role |
|---|---|---|
Selector string in $() | Yes (to populate) | What .selector stored |
| jQuery 1.3–2.x | Yes (to read it) | Property exists only there |
| Explicit plugin arg | Yes (modern) | Official replacement |
| Traversal chains | — | Make .selector unreliable |
set = jQuery("div.item")
// legacy: set.selector == "div.item"
set2 = set.eq(0)
// length is 1, but selector may still be "div.item"
// re-running that string would match ALL items — stale!
// modern plugin:
plugin(collection, selector, options)
// use the passed selector — do not read collection.selectorKeep these facts handy while reading legacy collections.
| Topic | Detail |
|---|---|
| Type | Property → String |
| Added | jQuery 1.3 |
| Deprecated | jQuery 1.7 |
| Removed | jQuery 3.0 |
| Meaning | Selector passed to jQuery() at creation |
| Replacement | Pass selector as a plugin parameter |
Toggle between jQuery 1.12 (property exists) and the modern pattern note. Source: jQuery API.
Examples 1–4 use jQuery 1.12.4. Example 5 uses jQuery 3.7.1 (modern pattern).
Inspect .selector after a simple CSS selection (jQuery 1.12).
var $items = jQuery("div.item");
$("#out").text(
"length: " + $items.length + "\n" +
"selector: " + $items.selector
);jQuery()..selector echoes what you typed.jQuery(sel, context)Scoped search still stores the selector string you passed.
var sidebar = document.getElementById("sidebar");
var $tags = jQuery(".tag", sidebar);
$("#out").text(
"count: " + $tags.length + "\n" +
"selector: " + $tags.selector + "\n" +
"context id: " + $tags.context.id
);".tag" — the string you passed..context holds the root node.sidebar variable in jQuery 3..eq()Narrowing the set does not give a selector that rebuilds only that subset.
var $items = jQuery("div.item");
var $first = $items.eq(0);
$("#out").text(
"After $(\"div.item\"): length " + $items.length +
", selector " + $items.selector + "\n" +
"After .eq(0): length " + $first.length +
", selector " + $first.selector + "\n" +
"Re-running that selector would match ALL items"
);.eq(0) keeps one element.No selector string was passed — often an empty .selector.
var el = document.getElementById("box");
var $fromSel = jQuery("#box");
var $fromNode = jQuery(el);
$("#out").text(
"From $(\"#box\"): \"" + $fromSel.selector + "\"\n" +
"From jQuery(el): \"" + $fromNode.selector + "\""
);.selector.Pass the selector explicitly — do not read .selector.
jQuery.fn.highlightBar = function (selector, options) {
var color = (options && options.color) || "#fef08a";
return this.filter(selector).css("background-color", color);
};
jQuery("div.bar").highlightBar("div.bar", { color: "#bbf7d0" });
$("#out").text(
"Plugin got selector: div.bar\n" +
".selector in 3.x: " + (jQuery("div.bar").selector === undefined
? "undefined (removed)" : jQuery("div.bar").selector)
);selector as argument 1."div.bar" explicitly..selector is gone; this pattern still works.Watch for these when reading legacy selector metadata.
.selector is undefined. Do not build new features on it.
.eq(), .filter(), .add(), and friends change the set without a trustworthy rebuild string.
$(element) or $("<div>") often yields an empty selector string.
Official fix: $.fn.foo = function(selector, options) { … } and repeat the selector at the call site.
.selector existed on collections in jQuery 1.3–2.x. It was deprecated in 1.7 and removed in jQuery 3.0. Not available in modern jQuery releases.
Historical collection metadata only. Use jQuery 1.12.x / 2.2.x for legacy demos. New code should pass selector strings explicitly.
Bottom line: Do not use in new projects. Migrate plugins to an explicit selector parameter. Keep studying it to understand older codebases and Migrate warnings.
| Approach | Cost | Best for |
|---|---|---|
Read .selector (1.x/2.x) | Free | Legacy debugging only |
| Re-query with stale string | Wrong results | Avoid |
| Explicit plugin selector arg | Free | Modern plugins |
| Own variable for the query | Free | Widgets and modules |
The cost is correctness, not CPU. Storing your own selector string (or accepting it as a parameter) is clearer and works in jQuery 3.
One line: .selector remembered creation-time query text — do not use it in jQuery 3; pass selectors explicitly.
Read the version string that still ships with every collection.
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