References

Beginner-friendly references for web development, with live, editable examples.

The JavaScript array.findLast() method

Method JavaScript All modern browsers Updated
Quick answer

The findLast() method returns the last element that passes your test, searching the array from the end backward, or undefined if none match. nums.findLast(n => n < 10) finds the last value under 10. It's the from-the-end counterpart of find().

Overview

findLast() works exactly like find() but searches from the end of the array toward the start, returning the first match it encounters that way — which is the last matching element in order. If nothing matches, you get undefined.

It saves you the awkward old workaround of reversing the array (or looping backward by hand) just to find the last item meeting a condition. The most recent log entry of a type, the last completed task, the final item below a threshold — all are one clean call.

Its index-returning partner is findLastIndex(), which gives the position instead of the element (or -1). Together, find()/findIndex() (from the start) and findLast()/findLastIndex() (from the end) cover searching by condition in either direction. The callback takes the usual element, index and array arguments.

Syntax

const element = array.findLast(callbackFn)

array.findLast((element, index, array) => {
  return /* true for the element you want */;
})

[1, 8, 3, 9, 2].findLast(n => n < 5)  // 2

Parameters

The array.findLast() method accepts the following parameters.

Parameter Description
callbackFn Test run on elements from the end backward until one returns truthy. Receives (element, index, array).
thisArg Optional. A value to use as this inside the callback.

Example

Live example 
<pre id="out" style="font:15px ui-monospace,monospace"></pre>
<script>
  const temps = [12, 18, 7, 21, 9];

  const lastCold = temps.findLast(t => t < 10);

  document.getElementById('out').textContent =
    'last temp under 10: ' + lastCold; // 9
</script>

Best practices

  • Use findLast() to find the last element meeting a condition without reversing the array.
  • Use findLastIndex() when you need the position of the last match instead.
  • For the first match (from the start), use find().
  • Handle the undefined result when nothing matches.

Frequently asked questions

What does findLast() do?
It returns the last element that passes the test, searching from the end of the array, or undefined if none match.
What is the difference between find() and findLast()?
find() returns the first match from the start; findLast() returns the last match (searching from the end).
How do I get the index of the last match?
Use findLastIndex(), which returns the position (or -1).
Is findLast() supported in all browsers?
Yes, in all current browsers. For older ones, reverse a copy and use find().
array.findIndex() array.findLastIndex()