$.each Utility

Loop over arrays and objects with the $.each helper.

Syntax$.each(collection, function (key, value) { ... });

There are two each forms:

  • $(selector).each(fn) — loops over matched DOM elements.
  • $.each(collection, fn) — loops over any array or object.
$.each(["a", "b", "c"], function (index, value) {
  console.log(index, value);
});

Example

Try it yourself
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When to use it

  • A currency converter uses $.each() on a rates object to build a dropdown option for every currency code.
  • A chart builder uses $.each() over an array of data points to compute the maximum value before scaling the axes.
  • A batch update script uses $.each() to send a separate AJAX request for each item in a selected list.

More examples

Iterate over an array with $.each()

$.each() calls the callback with the index and value for every element in the array.

Example · html
<ul id="fruits"></ul>
<script>
$(function () {
  var items = ["Apple", "Banana", "Cherry"];
  $.each(items, function (index, value) {
    $("#fruits").append("<li>" + index + ": " + value + "</li>");
  });
});
</script>

Iterate over a plain object

When the first argument is a plain object, $.each() iterates its own enumerable properties as key-value pairs.

Example · html
<dl id="info"></dl>
<script>
$(function () {
  var user = { name: "Alice", role: "Admin", active: true };
  $.each(user, function (key, val) {
    $("#info").append("<dt>" + key + "</dt><dd>" + val + "</dd>");
  });
});
</script>

Break early out of $.each()

Returning false from the callback stops $.each() early, equivalent to a break statement in a for loop.

Example · html
<p id="found"></p>
<script>
$(function () {
  var scores = [42, 78, 95, 61, 88];
  var firstPassing;
  $.each(scores, function (i, score) {
    if (score >= 90) {
      firstPassing = score;
      return false; // stops iteration
    }
  });
  $("#found").text("First passing score: " + firstPassing);
});
</script>

Discussion

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