Programmer Group

1. Introduction to jquery jQuery is an excellent JavaScript library that enables more functionality with minimal code characteristic: 1. Powerful selector function  $ ("selector") 2. Introduction to grammar  $ ("selector").action() 3. Implicit iteration  $ ("div").click();   // Five div will ...

New static functionArray.ofFunction type://Receive any number and type of parameters, and return an array of these parameters in the order they are passed in (...args?:any[])=>any[];Array.of is used to create a new Array instance with a variable number of parameters. The difference between it and creating arrays through the array constructor ...

1.mongodb official website MongoDB: the application data platform | MongoDB 2. Go to the official website of MongoDB and download MongoDB, MongoDB compass and Mongodb--database--tools 3. The operation of the MongoDB database by nodejs needs to rely on the third-party package mongoose of nodejs   Terminal instruction: npm install mongoo ...

1. ?? Non air operator In JS,?? Operators are called non airlift operators. If the first parameter is not null/undefined, the first parameter will be returned, otherwise the second parameter will be returned. For example, null ?? 5 // => 5 3 ?? 5 // => 3 When setting default values for variables, logic or operators were commonly used, ...

Before ECMAScript 6, arrays can be used to store values, and ECMAScript 6 adds two collection types: Set and WeakSet.SetSet set can use new to create an empty set:const s = new Set();You can also initialize an instance when creating a Set:const s = new Set(["Xiao Zhao", "Xiao Ming", "Kasumi "]);You can also customize the iterator when initializ ...

Before ECMASCript 6, constructor patterns and prototype patterns and their combinations were used to simulate the behavior of classes. However, these strategies have their own problems and corresponding compromises. The implementation of inheritance can also be very lengthy and confusing. Therefore, ECMASCript5 introduces a new class keyword to ...

1, BOM browser object model BOM - Browser Object Model The top-level object of BOM is winodw (an object. When you open a page, there is a window) All the variables you define in the group are under window. 1. Window size of browser Refers to the size of the browser's visual window. A scroll bar may appear in the browser   &nbsp ...

1, ES5 (ECMAScript version 5) 1. Add a function in the array Judgment function          every() is used to judge whether all elements in an array meet the requirements. The format is as follows: var Judgment result=array.every( function(Current element value n,Current subscript i,Current array ...

JavaScript is a descriptive scripting language, which is different from java or C# and other compiled languages. It does not need to be compiled into an intermediate language, but by browser Dynamically parse and execute. The code cannot be run directly. It needs to be compiled by the JavaScript compiler. Only the compiled code can be recognize ...

catalogue 1. Composition of JavaScript 1. Three cores 2. Common methods of window objects 2.if selection structure 3. Multiple if selection structure 4. Nested if selection structure 5.switch selection structure 6. Ternary expression 1. Composition of JavaScript 1. Three cores ESMAScript core syntax (Standard Specification) - > ...