The JavaScript exception "raw bracket is not allowed in regular expression with unicode flag" occurs when a Unicode-aware regular expression pattern contains a raw bracket ({, }, ]) that is not part of a quantifier or character class....Invalid cases js /{{MDN_Macro}}/u; /\[sic]/u; Valid cases js // All...
The JavaScript exception "can't redefine non-configurable property" occurs when it was
attempted to redefine a property, but that property is non-configurable.... js const obj = Object.create({});...redefine it later in the code. js const obj = Object.create({});...
Literals represent values in JavaScript. These are fixed values—not variables—that you literally provide in your script....examples of string literals: js "foo"; "bar"; "1234"; "one line...existing variable ( sales ). js const sales = "BMW"; function...
Error objects are thrown when runtime errors occur. The Error object can also be used as a base object for user-defined exceptions. See below for standard built-in error types....catch construct: js try { throw new Error("Whoops...with the instanceof keyword: js try { foo.bar(); } catch (e)...
элементы типа color предоставляют элемент пользовательского интерфейса, который позволяет пользователю указать цвет либо с помощью визуального интерфейса выбора цвета, либо путём ввода цвета в текстовое поле в шестнадцатеричном формате #rrggbb. Разрешены только простые цвета (без альфа-канала), хотя CSS colors имеет больше форматов, например названия цветов, функциональные обозначения и шестнадцатеричный формат с альфа-каналом....изменениями со временем значения цвета: js colorPicker.addEventListener("input"...адекватно реагировать в любом случае. js colorWell.select(); Вариации...
The Reflect namespace object contains static methods for invoking interceptable JavaScript object internal methods. The methods are the same as those of proxy handlers.... js const p = new Proxy( {}, { d...object contains certain properties js const duck = { name: "Maurice"...
Learn about the Image() constructor, including its syntax, code examples, specifications, and browser compatibility.... Syntax js new Image() new Image(width)...have the same values. Examples js const myImage = new Image(100...
The JavaScript exception "TypeError: can't set prototype: it would cause a prototype chain cycle" occurs when an object's prototype is set to an object such that the prototype chain becomes circular (a and b both have each other in their prototype chains).... Examples js const a = {}; Object.setPrototypeOf(a...cause a prototype chain cycle js const a = {}; const b = {}; const...
The JavaScript exception "more arguments needed" occurs when there is an error with how
a function is called. More arguments need to be provided....requires at least two arguments: js const obj = Object.create();...as the prototype, for example: js const obj = Object.create(null);...
Learn about the OffscreenCanvas interface, including its properties and methods, code examples, specifications, and browser compatibility.... js const one = document.getElementById("one")...The main.js script (main thread) may look like this: js const htmlCanvas...