Yahoo Web Search

Search results

1. Top results related to what is a set in javascript definition

   • What is the best way to write if-then-else for a large data set in JavaScript?

     Top Answer

     Answered Apr 13, 2022 · 2 votes

     A nested object indexed by age, then indexed by lifestyle would work.

     const calorieData = { 2: { 1: 1000, 2: 2000, }, 3: { 1: 1000, 2: 2000, }};// ...const calories = calorieData[age][lifestyle];

     A DRY-er version would use arrays instead, but it could require slightly more confusing code due to 0-based indicies.

     const calorieData = [ // omit index 0 , // omit index 1 , [1000, 2000], [1000, 2000], // ...];// ...// because lifestyle is 1-indexedconst calories = calorieData[age][lifestyle - 1];

     Check all answers on Stack Overflow

     1/5

   • What is the definition of a read-only property in JavaScript? What does it mean?

     Top Answer

     Answered Jan 01, 2021 · 6 votes

     A read-only property means it cannot be overwritten or assigned to. Any such assignment will silently do nothing in non-strict mode. E.g.:

     var obj = {};Object.defineProperty(obj, 'property', {value: 123, writeable: false})--// Assign 456 to obj.property using the . syntax, but it's still 123obj.property = 456;console.log(obj.property);// Assign 789 to obj.property using the [] syntax, but it's still 123obj['property'] = 789;console.log(obj['property']);

     Or just error out with a TypeError in strict mide:

     'use strict';-var obj = {};Object.defineProperty(obj, 'property', {value: 123, writeable: false})// Assign 456 to obj.property in strict mode will result in a TypeErrorobj.property = 456;console.log(obj.property);

     Check all answers on Stack Overflow

     2/5

   • What is a String in JavaScript ?

     In JavaScript, a string is a data type used to represent a sequence of characters. Strings are typically used to store and manipulate text-based data. Strings can contain letters, numbers, symbols, and whitespace characters.

     Example: Here, the variable greeting is assigned a string value "Hello, world!", which represents a common greeting message. The string is enclosed within double quotes ("), indicating its beginning and end.

     Javascript

     let greeting = "Hello, world!";console.log(greeting); // Output: Hello, world!-

     Output

     Hello, world!-

     Check all answers on Geeksforgeeks

     3/5

   • What is a "REPL" in javascript?

     Top Answer

     Answered Jun 20, 2020 · 75 votes

     Good information in the repl tag right here on Stack Overflow:

     About read-eval-print-loop

     A Read-Eval-Print Loop (REPL) is an interactive interpreter to a programming language. It originated with LISP systems, but many other languages (Python, Ruby, Haskell, Tcl, etc.) use REPL's to manage interactive sessions. They allow for simple experimentation with a language by bypassing the compile stage of the "code -> compile -> execute" cycle.

     There are 4 components to a REPL (named in LISP notation):

     • A read function, which reads input from the keyboard
     • An eval function, which evaluates code passed to it
     • A print function, which formats and displays results
     • A loop function, which runs the three previous commands until termination

     Check all answers on Stack Overflow

     4/5

   • What is a receiver in JavaScript?

     Top Answer

     Answered Jun 01, 2016 · 38 votes

     The receiver is the object in which the property lookup happens.

     So yes, if you use a.jump, a is the receiver.

     The concept is only relevant when you can execute arbitrary code when that property lookup happens. Basically, that means:

     var target = { get getReceiver() { return this; }};target.getReceiver; // targetvar inherits = Object.create(target);inherits.getReceiver; // inherits

     var proxy = new Proxy({}, { get: function(target, property, receiver) { return receiver; }});proxy.getReceiver; // proxyvar inherits = Object.create(proxy);inherits.getReceiver; // inherits

     • Accessor properties.You can access the receiver by using this inside the getter or setter. The receiver will usually be the object in which you defined the property, or another object which inherits from it. var target = { get getReceiver() { return this; }};target.getReceiver; // targetvar inherits = Object.create(target);inherits.getReceiver; // inheritsA built-in example is __proto__ , defined as a property of Object.prototype but expected to be got or set on other objects (receivers).
     • Proxy objectsProxy objects allow you to define get or set traps, which run a function when you attempt to get or set any property to the proxy. The receiver is provided as an argument of that function. The receiver will usually the Proxy object itself, or an object which inherits from it. var proxy = new Proxy({}, { get: function(target, property, receiver) { return receiver; }});proxy.getReceiver; // proxyvar inherits = Object.create(proxy);inherits.getReceiver; // inherits

     Note you can use Reflect.get

     or Reflect.set

     to specify arbitrary receivers:

     Reflect.get(target, "getReceiver", arbitraryValue); // arbitraryValue ¹Reflect.get(proxy, "getReceiver", arbitraryValue); // arbitraryValue

     ¹ If the getter was defined in non-strict mode, it will be Object(arbitraryValue)

     .

     The name "receiver" comes from the specification, see Object Internal Methods and Internal Slots

     • [[Get]]   (propertyKey, Receiver) → anyReturn the value of the property whose key is propertyKey from this object. If any ECMAScript code must be executed to retrieve the property value, Receiver is used as the this value when evaluating the code.
     • [[Set]]   (propertyKey, value, Receiver) → BooleanSet the value of the property whose key is propertyKey to value. If any ECMAScript code must be executed to set the property value, Receiver is used as the this value when evaluating the code. Returns true if the property value was set or false if it could not be set.

     Check all answers on Stack Overflow

     5/5

   Show moreShow less

2. developer.mozilla.org › en-US › docsSet - JavaScript | MDN - MDN Web Docs

   developer.mozilla.org › en-US › docs

   • Cached

   Jan 31, 2024 · The Set object lets you store unique values of any type, whether primitive values or object references. Description. Set objects are collections of values. A value in the set may only occur once; it is unique in the set's collection. You can iterate through the elements of a set in insertion order.

3. www.w3schools.com › js › js_setsJavaScript Sets - W3Schools

   www.w3schools.com › js › js_sets

   • Cached

   A JavaScript Set is a collection of unique values. Each value can only occur once in a Set. The values can be of any type, primitive values or objects.

4. www.geeksforgeeks.org › what-is-a-set-in-javascriptWhat is a Set in JavaScript? - GeeksforGeeks

   www.geeksforgeeks.org › what-is-a-set-in-javascript

   • Cached

   Jan 31, 2024 · In JavaScript, a Set is a built-in object that allows you to store unique values of any data type, whether primitive values or object references. Unlike arrays, which can contain duplicate values and are ordered by index, a Set only holds distinct values, and the order of insertion is maintained.

5. www.geeksforgeeks.org › sets-in-javascriptSets in JavaScript - GeeksforGeeks

   www.geeksforgeeks.org › sets-in-javascript

   • Cached

   6 days ago · Sets in JavaScript are collections of unique values, meaning no duplicates are allowed. They provide efficient ways to store and manage distinct elements. Sets support operations like adding, deleting, and checking the presence of items, enhancing performance for tasks requiring uniqueness.

   • Video Duration: 6 min

6. developer.mozilla.org › en-US › docsset - JavaScript | MDN - MDN Web Docs

   developer.mozilla.org › en-US › docs

   • Cached

   Jan 15, 2024 · The set syntax binds an object property to a function to be called when there is an attempt to set that property. It can also be used in classes.

7. blog.alexdevero.com › sets-in-javascriptIntroduction to Sets in JavaScript - All You Need to Know

   blog.alexdevero.com › sets-in-javascript

   • Cached

   Aug 17, 2020 · Sets are a new object type that was introduced to JavaScript with ES6 (ES2015). What sets allow you to do is to create collections of values. These values can be anything, from numbers and strings to arrays and objects. This doesn’t sound like something exciting. You can do the same thing with arrays.

8. People also ask

   What is a set in JavaScript?

   • In JavaScript, a Set is a built-in object that allows you to store unique values of any data type, whether primitive values or object references. Unlike arrays, which can contain duplicate values and are ordered by index, a Set only holds distinct values, and the order of insertion is maintained. Here are the key characteristics of a Set:

   What is a Set in JavaScript? - GeeksforGeeks

   www.geeksforgeeks.org/what-is-a-set-in-javascript/

   See all results for this question

   What is a set object?

   • The Set object lets you store unique values of any type, whether primitive values or object references. Set objects are collections of values. A value in the set may only occur once; it is unique in the set's collection. You can iterate through the elements of a set in insertion order.

   Set - JavaScript | MDN - MDN Web Docs

   developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set

   See all results for this question

   How to create a set in JavaScript?

   • A JavaScript Set is a collection of unique values. Each value can only occur once in a Set. The values can be of any type, primitive values or objects. You can create a JavaScript Set by: Pass an array to the new Set() constructor: Create a Set and add values: Create a Set and add variables: If you add equal elements, only the first will be saved:

   JavaScript Sets - W3Schools

   www.w3schools.com/js/js_sets.asp

   See all results for this question

   What is the difference between a set object and a symmetric set?

   • Symmetric difference: is the set of elements that are part of the sets, but not in their intersection. Set objects are collections of values. You can iterate through the elements of a set in insertion order. A value in the Set may only occur once; it is unique in the Set's collection. MDN

   Sets in JavaScript — the only explanation you will ever need

   dev.to/marcosmol204/sets-in-javascript-the-only-explanation-you-will-ever-need-4pl0

   See all results for this question

9. dev.to › marcosmol204 › sets-in-javascript-the-onlySets in JavaScript — the only explanation you will ever need

   dev.to › marcosmol204 › sets-in-javascript-the-only

   • Cached

   May 16, 2021 · Sets in JavaScript. Definition. Set objects are collections of values. You can iterate through the elements of a set in insertion order. A value in the Set may only occur once; it is unique in the Set's collection. MDN. Creating a set. The constructor takes an iterable object, eliminates all duplicated items, and returns an instance of Set.