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
Array()	It is used to create an array.

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

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

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

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