JavaScript Массив find()
Find the value of the first element with a value over 18:
const ages = [3, 10, 18, 20];
function checkAge(age) {
return age > 18;
}
function myFunction() {
document.getElementById("demo").innerHTML = ages.find(checkAge);
}
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Description
The find()
method returns the value of the first element that passes a test.
The find()
method executes a function for each array element.
The find()
method returns undefined
if no elements are found.
The find()
method does not execute the function for empty elements.
The find()
method does not change the original array.
Array Find Methods:
Method | Finds |
---|---|
indexOf() | The index of the first element with a specified value |
lastIndexOf() | The index of the last element with a specified value |
find() | The value of the first element that passes a test |
findIndex() | The index of the first element that passes a test |
findLast() | The value of the last element that passes a test |
findLastIndex() | The index of the last element that passes a test |
Syntax
array.find(function(currentValue, index, arr),thisValue)
Parameters
function() | Required. A function to run for each array element. |
currentValue | Required. The value of the current element. |
index | Optional. The index of the current element. |
arr | Optional. The array of the current element. |
thisValue | Optional. Default undefined .A value passed to the function as its this value. |
Return Value
Type | Description |
A value |
The value of the first element that pass the test. Otherwise it returns undefined . |
Find the value of the first element with a value above a specific number:
<p><input type="number" id="ageToCheck" value="18"></p>
<button onclick="myFunction()">Попробуй</button>
<p id="demo"></p>
<script>
const ages = [4, 12, 16, 20];
function checkAge(age) {
return age > document.getElementById("ageToCheck").value;
}
function myFunction() {
document.getElementById("demo").innerHTML = ages.find(checkAge);
}
</script>
Try it Yourself »
Array Tutorials:
Browser Support
find()
is an ECMAScript6 (ES6) feature.
ES6 (JavaScript 2015) is supported in all modern browsers since June 2017:
Chrome 51 | Edge 15 | Firefox 54 | Safari 10 | Opera 38 |
May 2016 | Apr 2017 | Jun 2017 | Sep 2016 | Jun 2016 |
find()
is not supported in Internet Explorer.