Use the Array isArray()
Method to Check if the object is Array in JavaScript. This method checks whether an object (or a variable) is an array or not. This method returns true
if the value is an array; otherwise returns false
.
Array.isArray(obj)
Check if the object is Array JavaScript
<!DOCTYPE html>
<html>
<body>
<script>
var v1 = {name: "John", age: 18};
var v2 = ["red", "green", "blue", "yellow"];
var v3 = [1, 2, 3, 4, 5];
var v4 = null;
console.log(Array.isArray(v1));
console.log(Array.isArray(v2));
console.log(Array.isArray(v3));
console.log(Array.isArray(v4));
</script>
</body>
</html>
Output:
For backward compatibility, you can add the following:
// Only implement if no native implementation is available
if (typeof Array.isArray === 'undefined') {
Array.isArray = function(obj) {
return Object.prototype.toString.call(obj) === '[object Array]';
}
};
If you use jQuery you can use jQuery.isArray(obj)
or $.isArray(obj)
. If you use Underscore.js you can use _.isArray(obj)
.
If you don’t need to detect arrays created in different frames you can also just use instanceof
:
obj instanceof Array
Source: stackoverflow.com
Another example
const myObject = [1, 2, 3];
if (Array.isArray(myObject)) {
console.log('myObject is an array');
} else {
console.log('myObject is not an array');
}
In this example, myObject
is an array, so the output will be “myObject is an array”. If you were to use a non-array object, the output would indicate that it’s not an array.
Comment if you have any doubts or suggestions on this JS Array topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version