JavaScript Array() Constructor
The Array() constructor is used to create Array objects and the array constructor can be called with or without a new keyword, both can create a new Array.
Syntax:
new Array(Value1, Value2, ...);
new Array(ArrayLength);
Array(Value1, Value2, ...);
Array(ArrayLength);
Parameters:
- ValueN: An array initialized by the given value, except in the case where only one value is provided to the array constructor and that value is a number. Unfortunately, the previous condition does not hold true if an array is built using the [ ]operator.
- arrayLength: If the Value is only one element that is also a number between 0 and 2^32 – 1 then an array object is created with the length property set to the array property.
Example 1: In this example, we will use the basic use of the Array() constructor.
// Using elements
const array1 = new Array(1, 2, 3, 4, 5)
// Using arrayLength
const array2 = new Array(10)
console.log(array1);
console.log(array2);
Output:
(5) [1, 2, 3, 4, 5]
(10) [empty × 10]
Example 2: In this example, we will use an array with a string value.
const language = new Array("HTML", "CSS", "Javascript");
console.log(language.length);
console.log(language[0]);
console.log(language[1]);
console.log(language[2]);
Output:
3
HTML
CSS
JavaScript
We have a complete list of Javascript Array() methods, to check those please go through this JavaScript Array Reference article.
Supported Browsers:
- Chrome 1
- Edge 12
- Firefox 1
- Opera 4
- Safari 1
JavaScript Array() Constructor- FAQs
How does the Array constructor work?
The
Arrayconstructor can be used in two main ways:
new Array(element0, element1, ..., elementN): Creates an array with the specified elements.new Array(arrayLength): Creates an array with the specified length, where all elements are initiallyundefined.
Can you use the Array constructor without the new keyword?
Yes, the Array constructor can be used without the new keyword, as it behaves the same way. For example, Array(3) and new Array(3) both create an array with a length of 3.
What happens if you pass a single number to the Array() constructor?
Passing a single number to the Array() constructor creates an array with that number as its length, with all elements initialized to undefined.
Can the Array() constructor create multidimensional arrays?
The Array() constructor does not directly create multidimensional arrays, but you can create them by nesting arrays within arrays.
What are some common use cases for the Array constructor?
Common use cases for the Array constructor include:
- Creating arrays with a specific length for later initialization.
- Dynamically creating arrays with elements provided as arguments.
- Using with higher-order functions like Array.from() and Array.of().
