Data Structures And Algorithms In Javascript

[Lucretia]

JavaScriptalgorithms are a set of programming instructions, known as inputs and outputs, that allow a data operation to function precisely at every execution. Meanwhile, JavaScript data structures are a method of organizing and storing data in a computer for efficient access and modification when necessary. A data structure contains the collection of data values, the operations that can be applied to the data and the relationships that exist between each piece of data.

Data structures are a method of storing and organizing data for efficient access and manipulation by all users and devices. Some common data structures that are used in JavaScript include stacks, queues, linked lists, sets, hash tables and trees, each of which makes it possible to call upon data existing in a specific state and use it in several ways.

Data structures allow algorithms to use data stored in the computer to execute a specific task laid out in a step-by-step manner by the algorithm. Algorithms can be written using any programming language, with JavaScript being no exception. This allows for client-side functionality such as sorting and searching.

Several pre-existing data structures exist to solve coding problems with efficiency, thereby reducing the number of programming hours needed to resolve an issue with a systematic method of storing and retrieving data. However, data structures exist to handle specific functions, which means the rest of the code that surrounds the data structure must be written properly in order for the data stored within to be accessible.

The fundamental knowledge attained through learning how to code in JavaScript, such as working with variables, arrays, objects, loops and functions, can then be written into algorithms, therby allowing programmers to manipulate strings, factorialize numbers and make advanced calculations.

I'd like to ask for recommendation of JavaScript library/libraries that supply an implementation of some basic data structures such as a priority queue, map with arbitrary keys, tries, graphs, etc. along with some algorithms that operate on them.

At the moment I'm mostly interested in priority queues (not to confuse with regular queues), graph implementations that aren't very intrusive as to the format of the input graph. For example they could use callbacks to traverse the structure of the graph rather than access some concrete properties with fixed names.

Probably most of what you want is built-in to Javascript in one way or another, or easy to put together with built-in functionality (native Javascript data structures are incredibly flexible). You might like JSClass.

Adding a link to a custom javascript library which provides Priority Queues, Tries, Basic Graph processing and other implementation, for future reference of the visitors to this thread . Check out dsjslib

Programming languages all have built-in data structures, but these often differ from one language to another. This article attempts to list the built-in data structures available in JavaScript and what properties they have. These can be used to build other data structures.

JavaScript is a dynamic language with dynamic types. Variables in JavaScript are not directly associated with any particular value type, and any variable can be assigned (and re-assigned) values of all types:

Implicit coercions are very convenient, but can create subtle bugs when conversions happen where they are not expected, or where they are expected to happen in the other direction (for example, string to number instead of number to string). For symbols and BigInts, JavaScript has intentionally disallowed certain implicit type conversions.

All primitive types, except null and undefined, have their corresponding object wrapper types, which provide useful methods for working with the primitive values. For example, the Number object provides methods like toExponential(). When a property is accessed on a primitive value, JavaScript automatically wraps the value into the corresponding wrapper object and accesses the property on the object instead. However, accessing a property on null or undefined throws a TypeError exception, which necessitates the introduction of the optional chaining operator.

The object wrapper classes' reference pages contain more information about the methods and properties available for each type, as well as detailed descriptions for the semantics of the primitive types themselves.

Conceptually, undefined indicates the absence of a value, while null indicates the absence of an object (which could also make up an excuse for typeof null === "object"). The language usually defaults to undefined when something is devoid of a value:

NaN ("Not a Number") is a special kind of number value that's typically encountered when the result of an arithmetic operation cannot be expressed as a number. It is also the only value in JavaScript that is not equal to itself.

Although a number is conceptually a "mathematical value" and is always implicitly floating-point-encoded, JavaScript provides bitwise operators. When applying bitwise operators, the number is first converted to a 32-bit integer.

Note: Although bitwise operators can be used to represent several Boolean values within a single number using bit masking, this is usually considered a bad practice. JavaScript offers other means to represent a set of Booleans (like an array of Booleans, or an object with Boolean values assigned to named properties). Bit masking also tends to make the code more difficult to read, understand, and maintain.

It may be necessary to use such techniques in very constrained environments, like when trying to cope with the limitations of local storage, or in extreme cases (such as when each bit over the network counts). This technique should only be considered when it is the last measure that can be taken to optimize size.

The BigInt type is a numeric primitive in JavaScript that can represent integers with arbitrary magnitude. With BigInts, you can safely store and operate on large integers even beyond the safe integer limit (Number.MAX_SAFE_INTEGER) for Numbers.

BigInt values are neither always more precise nor always less precise than numbers, since BigInts cannot represent fractional numbers, but can represent big integers more accurately. Neither type entails the other, and they are not mutually substitutable. A TypeError is thrown if BigInt values are mixed with regular numbers in arithmetic expressions, or if they are implicitly converted to each other.

The String type represents textual data and is encoded as a sequence of 16-bit unsigned integer values representing UTF-16 code units. Each element in the string occupies a position in the string. The first element is at index 0, the next at index 1, and so on. The length of a string is the number of UTF-16 code units in it, which may not correspond to the actual number of Unicode characters; see the String reference page for more details.

With conventions, it is possible to represent any data structure in a string. This does not make it a good idea. For instance, with a separator, one could emulate a list (while a JavaScript array would be more suitable). Unfortunately, when the separator is used in one of the "list" elements, then, the list is broken. An escape character can be chosen, etc. All of this requires conventions and creates an unnecessary maintenance burden.

A Symbol is a unique and immutable primitive value and may be used as the key of an Object property (see below). In some programming languages, Symbols are called "atoms". The purpose of symbols is to create unique property keys that are guaranteed not to clash with keys from other code.

In computer science, an object is a value in memory which is possibly referenced by an identifier. In JavaScript, objects are the only mutable values. Functions are, in fact, also objects with the additional capability of being callable.

In JavaScript, objects can be seen as a collection of properties. With the object literal syntax, a limited set of properties are initialized; then properties can be added and removed. Object properties are equivalent to key-value pairs. Property keys are either strings or symbols. When other types (such as numbers) are used to index objects, the values are implicitly converted to strings. Property values can be values of any type, including other objects, which enables building complex data structures.

There are two types of object properties: The data property and the accessor property. Each property has corresponding attributes. Each attribute is accessed internally by the JavaScript engine, but you can set them through Object.defineProperty(), or read them through Object.getOwnPropertyDescriptor(). You can read more about the various nuances on the Object.defineProperty() page.

Objects are ad-hoc key-value pairs, so they are often used as maps. However, there can be ergonomics, security, and performance issues. Use a Map for storing arbitrary data instead. The Map reference contains a more detailed discussion of the pros & cons between plain objects and maps for storing key-value associations.

Additionally, arrays inherit from Array.prototype, which provides a handful of convenient methods to manipulate arrays. For example, indexOf() searches a value in the array and push() appends an element to the array. This makes Arrays a perfect candidate to represent ordered lists.

Typed Arrays present an array-like view of an underlying binary data buffer, and offer many methods that have similar semantics to the array counterparts. "Typed array" is an umbrella term for a range of data structures, including Int8Array, Float32Array, etc. Check the typed array page for more information. Typed arrays are often used in conjunction with ArrayBuffer and DataView.

Usually, to bind data to a DOM node, one could set properties directly on the object, or use data-* attributes. This has the downside that the data is available to any script running in the same context. Maps and WeakMaps make it easy to privately bind data to an object.

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