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What is the JavaScript Array Method?

What is the JavaScript Array Method? Array methods in JavaScript are operations that can be performed on arrays, which include adding and removing elements, sorting, searching, and more.

These methods are also referred to as array functions or just array functions. The methods are standardized by ECMAScript, which means they are supported by all modern browsers except Internet Explorer versions 8 and earlier. They can also be supported by other web standards like HTML5, although it depends on how you write your code.

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What is array in JavaScript

The arraydata type in JavaScript represents an ordered collection of values. The elements of an array are accessed using indices. The length property of an array specifies how many elements it contains. Elements can be added or removed using various methods, includingpush(), pop() , shift(), unshift(), sort()and splice() . An individual element of an array can be retrieved by indexing it. Many other properties and methods of arrays exist which give JavaScript arrays a lot more functionality than just simple lists. All of these features make JavaScript arrays a powerful tool to use when developing applications in JavaScript. For example, they’re frequently used as parameters to callback functions and stored as member variables within objects.

Through learning array methods we create a strong base for our front-end development work. And it’s good to know what all these different methods do because we will be getting familiar with them all throughout our journey in learning Angular 2/4 development on front-end technologies as well! In case you missed my previous post where I went over array manipulation check that out HERE! With that said, let’s jump into some more array fun!! ❤.append(): The .append() method adds an element or elements to an array after any existing elements and returns a reference to the modified array. Example:[John, Mike, Sara] .append(Jane); //Outputs [John, Mike, Sara, Jane]

Javascript array method
Javascript array method

Now just one thing before you go ahead and start using append —make sure there are no duplicates in your current list. If there are duplicate values then they won’t get added until they’re sorted by their indices, which can also cause an error if they aren’t properly sorted then they get added into your final output! This isn’t a huge deal but it’s something to keep in mind when working with arrays on front-end development!

__.filter() : The .filter() method creates a new array with all elements that pass test implemented by the provided function, reusing existing filter rules for matching elements. Example: [1, 2, 3] .filter(x => x > 1) //Outputs [2, 3] You might have noticed that I used => instead of = earlier here; it’s because I’m showing how it would be written without destructuring assignment, as per my previous post HERE ! It works either way though so you could use whatever syntax seems easier for you to understand!

JavaScript Array Methods

Before diving into an array method, first, let’s define what we mean by an array method. An array method is a generic function that accepts an array as its input and returns another array. The output of one array method can be used as input to other methods or functions.

For example, suppose that you want to take a subset of items from a collection—the filter() method will select some items while leaving others out. You can then use filter() again on your filtered collection in order to produce a smaller set than you started with. You can chain these methods together using dot notation (e.g., foo. bar().baz()) like any other function calls. Here are several very common JavaScript array methods: * sort( ) * filter( ) * map( ) * reduce( ) * forEach( ) Example #1: var numbers = [4, 2, 3]; numbers.sort(); //=> [2, 3, 4] Example #2: var numbers = [4, 2, 3]; numbers.filter(function (n) ); //=> [5, 4] Numbers isn’t actually an array; it’s just a wrapper around integers that act as if they were arrays.

But you can also apply array methods to actual arrays. In most cases, it doesn’t matter whether or not you call them on wrappers or actual data types. Call them however feels most comfortable. What does matter is that whenever you pass an array as input to a method, whatever it returns will always be an array too! That means that regardless of whether we’re dealing with data types such as strings, objects, functions, etc…we can keep writing our code without ever having to cast anything between different data types! Well-defined conventions emerge naturally when working in a language where concepts aren’t tied to implementation details such as data type wrappers.

Check this: A Quick Guide On Working With JavaScript Arrays length

The forEach() Method

In JavaScript, there are two main ways to loop through array items. The first one, which I’ve discussed in previous articles, uses a for or while loop that increments a counter each time it loops through an item and compares it to a max value. The second method uses forEach(). This method differs from using a normal for/while loop because it lets you pass in an anonymous function as its argument that will be called on each item of your array. When we use a normal for/while loop, we have to define our own function and keep track of what indexes are available in our arrays—forEach() takes care of all that work for us. It’s more powerful than normal methods since you can do pretty much anything with those functions (including modifying your arrays if needed).

Plus, functions don’t evaluate their expressions until they’re executed (see hoisting), so when we create functions inside loops, it executes them multiple times but only gives them values from different iterations once (anonymous functions created outside loops always execute only once per iteration). Bypassing these new values into our inner functions every iteration, instead of just once at a certain index like other methods do, forEach() also allows us to modify any part of our arrays by returning those modified values into them. That means whatever tasks these inner functions perform can affect all of their items instead of just their indexes.

Check this: Javascript array slice method

There aren’t many downsides to using forEach(), though it isn’t very flexible compared to standard JavaScript loops. If all you need is to iterate over an array and apply some logic to each item based on its position, then forEach() works great! If you have more complex requirements, though, defining a custom function may help make things clearer for everyone else reading your code too. That way when someone sees how_I_counted_the_elements(array) or getsItemsInOrder(array), they know exactly how that code works without having to dig around in it. Plus they won’t be confused by missing logic like if statements or duplicate logic between sections of your code—remember: DRY, right?

Examples of JavaScript Array Methods in Action

There are more than 60 built-in array methods in JavaScript, so we can’t cover them all here. However, if you’re just getting started with arrays and want to get a feel for how they work, try taking advantage of some of these common array methods. For example, using code snippets like these will help you determine whether elements exist within arrays: filter() : Returns a new array that contains only elements that pass test(s) defined by provided function(s). map(): Returns a new array with results of calling a provided function on every element in the calling array. reduce() : Combines elements of an array into one value by iterating through each element and accumulating them.

In math terms, reduce would take 4 + 5 = ? and return 9. This can be done by adding two numbers together (the addition operator (+)) or multiplying numbers together (the multiplication operator (*)). sort(): Returns a sorted version of an array. You might use sort to alphabetize or otherwise reorder items in your application’s menu system, for instance. unshift() / shift():

The unshift method appends one or more elements to an array; it behaves identically to push(), except it does not alter its argument. The shift method removes and returns the first element from an array, shortening it by 1. Note that arguments[] cannot be empty when either unshift ()or shift ()is called.. pop() / splice(): Both pop() and splice() remove an element from an array. Unlike shift(), both also let you specify where to delete the item being removed—meaning a different item is removed from each position within arguments []. Try using these three pop examples: once (), last (), and random ().

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Al Nahian

You know what, you're doing your best. Thank you for investing your valuable time & energy to help us ❤.