JavaScript Arrays

JavaScript Arrays – Arrays are used to store multiple elements in a single variable. Elements in an array are assumed to represent members belonging to a type. For example, prime numbers, names of students in a class, items to be displayed under a category, etc. Array object in JavaScript helps in the construction of arrays. It also provides methods that help in accessing or transforming or applying functions on the elements of array.

Syntax

The syntax to initialize an Array in JavaScript is

var arrayName = [ element1, element2, .. elementN ]

where arrayName is the name given to the array and would be referenced by this name in the script.

During initialization, N number of Elements could be grouped as an array, separated by comma (,).

To access an element of an array, you may use index [0:N-1] with arrayName as shown in the following.

arrayName[i]

accesses (i+1)th element of the array.

JavaScript – Number Array

To initialize a JavaScript Array Object with Numbers, and access its elements :

var numbers = [12, 56, 8];
console.log(numbers[1]);
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JavaScript – String Array

To initialize a JavaScript Array Object with Strings, and access its elements :

var names = ['Arjun', 'Akhil', 'Varma'];
console.log(names[1]);
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JavaScript – Boolean Array

To initialize a JavaScript Array Object with Numbers, and access its elements :

var outs = [true, false, true, true];
  console.log(outs[1]);
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JavaScript – Object Array

To initialize a JavaScript Array Object with Numbers, and access its elements :

var mango = {type:"fruit", native:"India"};
var maple = {type:"tree", native:"Canada"};
      
var specials = [mango, maple];

console.log(specials[0].native);
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JavaScript – Heterogeneous Array

Heterogeneous Array is an array that contain elements of different primitive types and ofcourse other objects. A JavaScript Array object can contain another array as an element, along with numbers, strings or booleans.

To initialize a JavaScript Array Object with Heterogeneous types of elements, and access its elements :

var arjun = ['Arjun', 25, {native:"India", gender:"Male"}];
console.log(arjun[0]);
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Conclusion

In this JavaScript Tutorial, we have learnt about JavaScript Arrays, how they are initialized etc. In our next tutorial – JavaScript – Array Methods, we shall learn about different methods that an Array have.