the murmurous sea

1. object 2. represents the eventual completion (or failure) of an asynchronous operation and its resulting value. 3. allows you to associate handlers with an asynchronous action's eventual success value or failure reason. 4. guaranteed to be asynchronous : Therefore, an action for an already "settled" promise will occur only after the stack has cleared and a clock-tick has passed. : The effect ..

After ECMAScript, JavaScript used to have 6 data types. Primitive data type - string - number - bigint - boolean - undefined Object type Object(object, array, function) After ES6(ECMAScript2015), symbol is added as a 7th data type. about null ▼ 더보기 There also is null, which is seemingly primitive, but indeed is a special case for every Object: and any structured type is derived from null by the ..

split() go to see the post Array.prototype.join() 1. Method 2. Convert the elements of an array into a string 3. The string conversions of all array elements are joined into one string. 4. Creates and returns a new string by concatenating all of the elements in an array (or an array-like object▼). 더보기 The following example joins an array-like object (arguments), by calling Function.prototype.cal..

▼Prior knowledge 더보기 Prarmeters and Arguments : Function parameters are the names listed in the function definition. : Function arguments are the real values passed to (and received by) the function. Parameter Rules : JavaScript function definitions do not specify data types for parameters. : JavaScript functions do not perform type checking on the passed arguments. : JavaScript functions do not..

Using Set What is Set 더보기 1. collections of values. 2. store unique values of any type, whether primitive values or object references. 3. A value in the Set may only occur once; it is unique in the Set's collection. : Because each value in the Set has to be unique, the value equality will be checked. 4. earlier version of ECMAScript specification, +0 (which is strictly equal to -0) and -0 were d..

The String() function returns the same value as toString() of the individual objects. But String() : can use it on values that are undefined or null. toString() : will produce a TypeError exception. String will often call an object's toString() anyway, so its a safer way of doing that. String() 1. Constructor 2. Standard built-in objects 3. to create a new String object. 4. It performs type conv..

The difference is: The call() method takes arguments separately. The apply() method takes arguments as an array. www.w3schools.com/js/js_function_call.asp JavaScript Function call() JavaScript Function Call Method Reuse With the call() method, you can write a method that can be used on different objects. All Functions are Methods In JavaScript all functions are object methods. If a function is n..

**Before jump to the main content. JavaScript supports different kinds of loops: for loops through a block of code a number of times for...in loops through the properties of an object for...of loops through the values of an iterable object while loops through a block of code while a specified condition is true do...while loops through a block of code once, and then repeats the loop while a speci..

Object.keys() 1. method 2. iterated in the same order that a normal loop would. [Syntax] Object.keys(obj) [Return Value] An array : of strings : of a given object's own enumerable property names : that represent all the enumerable properties of the given object. : The ordering of the properties is the same as the obj. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objec..