JavaScript Array Reference

JavaScript Array is used to store multiple elements in a single variable. It is often used when we want to store a list of elements and access them by a single variable. Unlike most languages where the array is a reference to the multiple variables, in JavaScript array is a single variable that stores multiple elements.

Syntax:

const arr = ["Item1", "Item2", "Item3", ...];

Example: In this example, we are creating an array and copying its items to another array, and displaying its items.

JavaScript

<script>
    // Create and initialize an array
    let items = ['GFG', 'Geeks', 'G4G'];

    // Display the array items
    console.log(items);

    // Create a new empty array
    let new_Array = [];

    // forEach loop to push elements
    // into new array
    items.forEach(function (item) {
        new_Array.push(item);
    });

    // Display the new array of items
    console.log(new_Array);
</script>

Output:

Original Array: GFG, Geeks, G4G
Copied Array: GFG, Geeks, G4G

The complete list of JavaScript Array is listed below:

JavaScript Array Constructor: In JavaScript, a constructor gets called when an object is created using the new keyword.

Constructor	Descriptions	Examples
Array()	It is used to create an array.	Try

JavaScript Array Properties: A JavaScript property is a member of an object that associates a key with a value.

• Instance Property: An instance property is a property that has a new copy for every new instance of the class.

  Instance Properties	Descriptions	Examples
  constructor	Returns only reference of the function and does not return the name of the function.	Try
  length	Set or return the number of elements in an array.	Try

JavaScript Array Methods: JavaScript methods are actions that can be performed on objects.

• Static Method: If the method is called using the array class itself then it is called a static method.

  Static Methods	Descriptions	Examples
  from()	Returns an array object from any object with a length property or an iterable object.	Try
  isArray()	Returns true if the argument passed is an array else it returns false.	Try
  of()	Creates a new array instance with variables present as the argument of the function.	Try

• Instance Method: If the method is called on an instance of a array then it is called an instance method.

  Instance Methods	Descriptions	Examples
  at()	Returns the element of that index	Try
  concat()	Merge two or more arrays together.	Try
  copyWithin()	Copies part of an array to the same array itself and returns.	Try
  entries()	Fetch all the entries of the same data structure.	Try
  every()	checks that whether all the elements of the array satisfy the given condition.	Try
  fill()	Fill the array with a given static value.	Try
  filter()	Builds a new array containing elements that satisfy a function’s test.	Try
  find()	Get the value of the first element in the array that satisfies the provided condition.	Try
  findIndex()	Return the first index of the element in a given array that satisfies the provided testing function.	Try
  flat()	Flatten an array, to reduce the nesting of an array.	Try
  flatMap()	This is used to flatten the input array element into a new array.	Try
  forEach()	It is provided a function once for each element of the array.	Try
  includes()	If an array contains the certain value, it returns true.	Try
  indexOf()	Return the first index at which a given element may be found, or -1 if it does not exist.	Try
  join()	Join the elements of an array into a string.	Try
  keys()	Return a new array iterator which contains the keys for each index in the given input array.	Try
  lastIndexOf()	Return the last index at which a given element may be found, or -1 if it does not exist.	Try
  map()	Calls the argument function once for each element of the given array in order.	Try
  pop()	Remove the last element of the array and also returns the removed element.	Try
  push()	Push one or more values into the array.	Try
  reduce()	Reduce the array to a single value and executes a provided function for each value of the array.	Try
  reduceRight()	Convert elements of the given array from right to left to a single value.	Try
  reverse()	This is used for the in-place reversal of the array.	Try
  shift()	Removes the first element of the array thus reducing the size of the original array by 1.	Try
  slice()	Returns a new array containing a portion of the array on which it is implemented.	Try
  some()	Each array element’s callback function is run once.	Try
  sort()	Sort an array in place in a given order according to the compare() function.	Try
  splice()	Modify the contents of an array by removing the existing elements.	Try
  toLocaleString()	Convert the elements of the given array to string.	Try
  toString()	Return the string representation of the array elements.	Try
  unshift()	Add one or more elements to the beginning of the given array.	Try
  values()	Return a new array Iterator object that contains the values for each index in the array.	Try