The JavaScript exception "invalid unicode escape in regular expression" occurs when the \c and \u character escapes are not followed by valid characters.... Examples Invalid cases js /\u{123456}/u; // Unicode code.../\c1/u; // Not a letter Valid cases js /\u0065/u; // Lowercase "e" /\u{1F600}/u;...
Learn about the HTMLInputElement.setCustomValidity() method, including its syntax, code examples, specifications, and browser compatibility.... Syntax js setCustomValidity(message) Parameters...reportValidity() method on the element. js function validate(inputID) {...
Learn about the paste event, including its type, syntax, and properties, specifications and browser compatibility.... js addEventListener("paste", (event)...<h3>Log:</h3> <p id="log"></p> JavaScript js function logCopy(event) { log...
Learn about the cancel event, including its type and syntax, code examples, specifications, and browser compatibility.... js addEventListener("cancel", (event)...margin: 0.5rem; } JavaScript js const result = document.querySelector("...
The JavaScript exception "functions cannot be labelled" occurs when a function declaration has a label before it....property key in an object literal: js const createObj = () => { greet:...object literal in parentheses: js const createObj = () => ({ greet:...
A WeakSet is a collection of garbage-collectable values, including objects and non-registered symbols. A value in the WeakSet may only occur once. It is unique in the WeakSet's collection....s are ideal for this purpose: js // Execute a callback on everything...Examples Using the WeakSet object js const ws = new WeakSet(); const...
Learn about the Window.fetch() method, including its syntax, code examples, specifications, and browser compatibility.... Syntax js fetch(resource) fetch(resource...display it in an <img> element. js const myImage = document.querySelector("img");...
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...