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Arrays provide a lot of methods.… So, special methods should be used. The arr.splice method is a Swiss army knife for arrays.… This method is easy to grasp by examples.… Here the arr.find(fn) method comes in handy.… Most methods support “thisArg”.Almost all array methods that call functions – like find, filter, map,

They also provide methods to call as such.… So here we’ve made an object john with the method sayHi.… It would be great to access them using methods.… Thus, they provide different sets of methods.… That method runs and returns a new string (shown by alert).

A function that is a property of an object is called its method.… So, here we’ve got a method sayHi of the object user.… Method shorthand.There exists a shorter syntax for methods in an object literal:… To access the object, a method can use the this keyword.… Methods allow objects to “act” like object.doSomething().

JavaScript provides methods: JSON.stringify to convert objects into JSON.… Namely: Function properties (methods). Symbolic keys and values.… That’s because all dates have a built-in toJSON method which returns such kind of string.… JSON.parse.To decode a JSON-string, we need another method named JSON.parse.… Both methods support transformer functions for smart reading/writing.

We can also assign a method to the class as a whole. Such methods are called static.… It’s not a method of an article, but rather of the whole class.… Another example would be a so-called “factory” method.… Once again, that’s not a method of an article, but a method of the whole class.… For example, a method for comparison Article.compare(article1, article2) or a factory method Article.createTodays

A popup window is one of the oldest methods to show additional document to user.… Only popups To prevent abuse, the browser usually blocks these methods.… Move/resize methods do not work for maximized/minimized windows.… Focus/blur on a window.Theoretically, there are window.focus() and window.blur() methods to focus/unfocus… Methods focus() and blur() allow to focus/unfocus a window. But they don’t work all the time.

Here is an example of all three methods:

In this article we’ll cover various methods that work with regexps in-depth. str.match(regexp).The method… The method str.matchAll(regexp) is a “newer, improved” variant of str.match.… as finding them all with str.matchAll(regexp). str.replace(str|regexp, str|func).This is a generic method… Unlike previous methods, it’s called on a regexp, not on a string.… Or instead of calling methods on regexp, use string methods str.match/search/..., they don’t use lastIndex

In the first chapter of this section, we mentioned that there are modern methods to setup a prototype… The modern methods to get/set a prototype are: Object.getPrototypeOf(obj) – returns the [[Prototype]… Although, there’s a special method for this too: Object.create(proto[, descriptors]) – creates an empty… The Object.create method… Unexpected things also may happen when assigning to obj.toString, as it’s a built-in object method.

The method form.submit() allows to initiate form sending from JavaScript.… the demo: Method

Internal and external interface.In object-oriented programming, properties and methods are split into… two groups: Internal interface – methods and properties, accessible from other methods of the class… External interface – methods and properties, accessible also from outside the class.… Until now we were only using public properties and methods.… _power from the methods of the new class. So protected fields are naturally inheritable.

That’s a built-in toString method, but where is it? The obj is empty!… They provide the methods and disappear.… If two libraries add a method String.prototype.show, then one of them will be overwriting the method… That’s when we take a method from one object and copy it into another.… Some methods of native prototypes are often borrowed.

We do something in our method, but call the parent method before/after it or in the process.… A method, such as longEar.eat, knows its [[HomeObject]] and takes the parent method from its prototype… But for objects, methods must be specified exactly as method(), not as "method: function()"… When overriding another method: We can use super.method() in a Child method to call Parent method.… That’s how super resolves parent methods.

class methods, which would result in a syntax error.… The function code is taken from the constructor method (assumed empty if we don’t write such method).… So the object has access to class methods.… Class methods are non-enumerable.… Previously, our classes only had methods.

In the previous chapter we saw methods map.keys(), map.values(), map.entries().… These methods are generic, there is a common agreement to use them for data structures.… So we may have an object of our own like data that implements its own data.values() method.… Also, there exist a method Reflect.ownKeys(obj) that returns all keys.… Use array methods on that array, e.g. map, to transform these key/value pairs.

No matter where the method is found: in an object or its prototype.… In a method call, this is always the object before the dot.… Where is the method rabbit.hasOwnProperty coming from? We did not define it.… So methods always work with the current object even if they are inherited.… All other key/value-getting methods only operate on the object itself.

As defined in Wikipedia, a mixin is a class containing methods that can be used by other classes without… In other words, a mixin provides methods that implement a certain behavior, but we do not use it alone… As super looks for parent methods in [[HomeObject]].… …And the method .off(name, handler) that removes the handler listener.… Mixins may become a point of conflict if they accidentally overwrite existing class methods.

](hint) – the method with the symbolic key Symbol.toPrimitive (system symbol), if such method exists,… Symbol.toPrimitive.Let’s start from the first method.… These methods must return a primitive value.… By default, a plain object has following toString and valueOf methods: The toString method returns a… The valueOf method returns the object itself.

There’s a special method append for that: document.body.append(div).… So, these methods can only be used to insert DOM nodes or text pieces.… Old-school insert/remove methods.… These methods come from really ancient times.… But usually the returned value is not used, we just run the method.

Built-in methods like filter, map and others – return new objects of exactly the inherited type PowerArray… That’s actually very cool, because we can keep using PowerArray methods further on the result.… No static inheritance in built-ins.Built-in objects have their own static methods, for instance Object.keys… Normally, when one class extends another, both static and non-static methods are inherited.… That was thoroughly explained in the article Static properties and methods.

When for..of starts, it calls that method once (or errors if not found).… The method must return an iterator – an object with the method next.… The range itself does not have the next() method.… Then we can call array methods on it.… Such objects may also have other properties and methods, but lack the built-in methods of arrays.

There are additional searching methods for that. document.getElementById or just id.If an element has… the id attribute, we can get the element using the method document.getElementById(id), no matter where… In real life document.getElementById is the preferred method.… In other words, the method closest goes up from the element and checks each of parents.… Summary.There are 6 main methods to search for nodes in DOM: Method Searches by...

A preflight request uses the method OPTIONS, no body and three headers: Access-Control-Request-Method… header has the method of the unsafe request.… Access-Control-Allow-Methods must have the allowed method.… Access-Control-Request-Method – requested method.… has requested method.

For instance [[Get]], the internal method to read a property, [[Set]], the internal method to write a… For every internal method, there’s a trap in this table: the name of the method that we can add to the… Its methods are minimal wrappers around the internal methods.… Built-in methods access them directly, not via [[Get]]/[[Set]] internal methods.… The built-in method Map.prototype.set method tries to access the internal property this.

The fetch() method is modern and versatile, so we’ll start with it.… Response provides multiple promise-based methods to access the body in various formats: response.text… It’s not exactly a Map, but it has similar methods to get individual headers by name or iterate over… POST requests.To make a POST request, or a request with another method, we need to use fetch options:… method – HTTP-method, e.g.

In JavaScript, they are available via the RegExp object, as well as being integrated in methods of strings… The method str.match(regexp) finds all matches of regexp in the string str.… Full information about the methods is given in the article Methods of RegExp and String. Summary.… The method str.replace(regexp, replacement) replaces matches found using regexp with replacement: all… The method regexp.test(str) returns true if there’s at least one match, otherwise, it returns false.

A dynamically evaluated method call can lose this.… Then the method is immediately called with parentheses (). But it doesn’t work correctly!… This works (object dot method): This… doesn’t (evaluated method): Why?… That’s for the subsequent method call () to get the object and set this to it.

When passing object methods as callbacks, for instance to setTimeout, there’s a known problem: “losing… Once a method is passed somewhere separately from the object – this is lost.… Solution 2: bind.Functions provide a built-in method bind that allows to fix this.… For example, for an object method. The native bind does not allow that.… Usually we apply bind to fix this for an object method, so that we can pass it somewhere.

That can be implemented using a special method with the name Symbol.iterator: This method is called… For each iteration, the next() method is invoked for the next value.… The next() method should return a promise (to be fulfilled with the next value).… This method must return the object with next() method returning a promise (2).… The next() method doesn’t have to be async, it may be a regular method returning a promise, but async

func.call” for the context.The caching decorator mentioned above is not suited to work with object methods… Now how to cache the multi-argument worker.slow method?… That’s because the internal algorithm of the native method arr.join(glue) is very simple.… borrowing when we take a method from an object and call it in the context of another object.… It is quite common to take array methods and apply them to arguments.

The special thing about FormData is that network methods, such as fetch, can accept a FormData object… FormData Methods.We can modify fields in FormData with methods: formData.append(name, value) – add a… There’s also method set, with the same syntax as append.… Summary.FormData objects are used to capture HTML form and submit it using fetch or another network method… Other methods are: formData.delete(name) formData.get(name) formData.has(name) That’s it!

Methods and properties are: new Map() – creates the map. map.set(key, value) – stores the value by the… So we should use map methods: set, get and so on. Map can also use objects as keys.… Besides that, Map has a built-in forEach method, similar to Array:… Its main methods are: new Set([iterable]) – creates the set, and if an iterable object is provided (… Additional convenient methods, the size property. Set – is a collection of unique values.

Accessing characters.To get a character at position pos, use square brackets [pos] or call the method… Let’s recap these methods to avoid any confusion: method selects… negatives slice(start, end)… It provides a special method to compare strings in different languages, following their rules.… To get a character, use: [] or at method. To get a substring, use: slice or substring.… Strings also have methods for doing search/replace with regular expressions.

The fetch method allows to track download progress.… Unlike response.text(), response.json() and other methods, response.body gives full control over the… method to get the result.… Unfortunately, there’s no single method that concatenates those, so there’s some code to do that: We… Then use .set(chunk, position) method to copy each chunk one after another in it.

Second, it represents the “browser window” and provides methods to control it.… There are more window-specific methods… Properties and methods are described in the specification: DOM Living Standard.… also a part of the BOM: they are not directly related to the document, but represent pure browser methods… It takes the DOM specification and extends it with many additional properties and methods.

We’ve already seen setStart and setEnd, here are other similar methods.… With these methods we can do basically anything with selected nodes.… Now let’s see these methods in action.… That’s a somewhat complex method.… For input, textarea: additional methods and properties.

Methods pop/push, shift/unshift.A queue is one of the most common uses of an array.… They provide special methods for that.… To extract an element from the end, the pop method cleans the index and shortens length.… The similar thing with the push method.… in the next chapter Array methods.

It stores the date, time and provides methods for date/time management.… This method is deprecated. It returns 2-digit year sometimes. Please never use it.… All the methods above return the components relative to the local time zone.… There’s a special method Date.now() that returns the current timestamp.… Date.parse from a string.The method Date.parse(str) can read a date from a string.

Right now, there’s another, more modern method fetch, that somewhat deprecates XMLHttpRequest.… specifies the main parameters of the request: method – HTTP-method.… This method opens the connection and sends the request to server.… Some request methods like GET do not have a body.… There’s another object, without methods, exclusively to track upload events: xhr.upload.

But there are additional methods and peculiarities to consider.… The method scrollBy(x,y) scrolls the page relative to its current position.… The button below demonstrates this: window.scrollBy(0,10) The method scrollTo(pageX,pageY) scrolls… To scroll to the very beginning, we can use scrollTo(0,0). window.scrollTo(0,0) These methods work… The drawback of the method is that the scrollbar disappears.

They share the same set of methods and properties.… TypedArray methods.TypedArray has regular Array methods, with notable exceptions.… No concat method.… With DataView we access the data with methods like .getUint8(i) or .getUint16(i).… We choose the format at method call time instead of the construction time.

These methods are not a part of JavaScript specification.… But most environments have the internal scheduler and provide these methods.… For instance, Node.js returns a timer object with additional methods.… Again, there is no universal specification for these methods, so that’s fine.… The nested setTimeout is a more flexible method than setInterval.

return not exactly a promise, but a so-called “thenable” object – an arbitrary object that has a method… named then, then it calls that method providing native functions resolve, reject as arguments (similar… We’ll use the fetch method to load the information about the user from the remote server.… To read the full response, we should call the method response.text(): it returns a promise that resolves… The response object returned from fetch also includes the method

matchAll is a new method, polyfill may be needed The method matchAll is not supported in… When we search for all matches (flag g), the match method does not return contents for groups.… To get them, we should search using the method str.matchAll(regexp).… Why is the method designed like that? The reason is simple – for the optimization.… The method str.matchAll always returns capturing groups.

we really need to make constant object properties, it’s also possible, but using totally different methods… We can also use the method… There are also other methods of cloning an object, e.g. using the spread syntax clone = {...user}, covered… There’s structuredClone method that implements deep cloning. structuredClone.The call structuredClone… To handle such complex cases we may need to use a combination of cloning methods, write custom code or

We can also set a custom logic in the static method Symbol.hasInstance.… The algorithm of obj instanceof Class works roughly as follows: If there’s a static method Symbol.hasInstance… Animal compares with Animal.prototype: By the way, there’s also a method… Summary.Let’s summarize the type-checking methods that we know: works for returns typeof primitives

The constructor: The main methods:… The choice of read* method depends on which format we prefer, how we’re going to use the data.… Its reading methods read* do not generate events, but rather return a result, as regular functions do… In addition to Blob methods and properties, File objects also have name and lastModified properties,

It has a single method abort(), And a single property signal that allows to set event listeners on it… AbortController as a fetch option: The fetch method… AbortController is a simple object that generates an abort event on its signal property when the abort() method

There are 6 static methods in the Promise class. We’ll quickly cover their use cases here.… Same as: In practice, this method is… Summary.There are 6 static methods of Promise class: Promise.all(promises) – waits for all promises… Promise.allSettled(promises) (recently added method) – waits for all promises to settle and returns their… Promise.any(promises) (recently added method) – waits for the first promise to fulfill, and its result

We can add a method… We can also modify built-in prototypes like Element.prototype and add new methods… So, DOM properties and methods… All attributes are accessible by using the following methods: elem.hasAttribute(name) – checks for existence… These methods operate exactly with what’s written in HTML.