Table of Contents 1. Introduction to Ajax 1. The concept of asynchronous and synchronized 2. Why is it said that synchronous requests will “reload the entire page”, while asynchronous requests “will only load part of the page”. What does this mean? 3. Functions and advantages of Ajax Function Advantage 4.Why is Ajax called asynchronous javascript […]
Tag: callback
Callback Hell in Node.js
Gathering sand into a tower, making a little progress every day ? Column introduction Front-end Getting Started Tour: Exploring the Wonderful World of Web Development Welcome to the Front-End Getting Started Tour! If you are interested, you can subscribe to this column! This column is tailor-made for those who are interested in web development and […]
JavaScriptEvent monitoring, event delegation and callback functions
1. Event monitoring on method: box.onclick = function(){}, but this method will be overwritten. You can unbind the event by directly overwriting it with null. addEventListener is a method specifically used by DOM objects to add event listening. Its first two parameters are [event type] and [event callback], and the third parameter of addEventListener is […]
A brief discussion on React hook functions useMemo and useCallback
Foreword There are many officially provided hooks in React, such as useEffect, useState, useMemo, and useCallback. Some beginners can’t tell what scenarios useMemo and useCallback are suitable for. Today we will talk about these two hook functions. useMemo It is used to optimize rendering performance. useMemo will receive a callback function wrapped by an arrow […]
2310C++ callback to waiter
original This article uses metaprogramming technology to automatically adapt the callback interface function and convert it into a waiter object. Usage example: name callback {<!– –> Use schedule = list<function<empty()>>; NullAdd(Scheduling&_Scheduling, Int&&_a, Constant&_b, Double_c, Double_d, Function<null(Integer, Double)>_f){< !– –> _Scheduling.Original ([_f, x = _a + _b, y = _c + _d]{<!– –>_f(x, y);}); } empty […]
[C Language] Debugging questionable function pointers and writing callback functions (Callback function parameters in the structure and false callback function __weak declaration)
[C Language] Debugging questionable function pointers and writing callback functions (Callback function parameters in the structure and false callback function __weak declaration) Article directory Debugging questionable function pointers function pointer function call Writing callback function callback function inside the structure fake callback function Appendix: Compressed strings, big and small endian format conversion Compressed string floating […]
NodeJS callback hell and Promise optimization
There are many asynchronous APIs in NodeJS, such as the common readFile method of the fs module. Although there is a synchronous version of readFileSync, its performance is definitely not as good as the former. So let’s start with the asynchronous version of readFile: const fs = require(‘fs’); fs.readFile(‘./a.txt’, ‘utf-8’, function(error, data) { if (!error) […]
C language function pointer as function parameter (callback function)
Use the callback function to print any type of data Implement printing of int type data //Provide a printing function that can print any type of data //Give the printing requirements to the user void myPrintInt(void *data){ int *p = data; printf(“%d\ “, *p); } void printText(void *data, void(*myPrint)(void *)){ myPrint(data); } //Print int type […]
H5 new API | requestIdleCallback – requestAnimationFram
Article directory Browser rendering mechanism event loop mechanism Macro queue and micro queue Event loop process in browser requestAnimationFrame(rAF) requestAnimationFrame API requestIdleCallback requestIdleCallback API Task splitting Usage scenarios of requestIdleCallback Browser rendering mechanism Will each round of Event Loop be accompanied by rendering? At which stage is requestAnimationFrame executed, before or after rendering? Before or […]
Web APIs – environment object this and callback function
1. Environment object Environment object: refers to the special variable this inside the function, which represents the environment in which the current function is running. Function: clarifying the point of this can make the code more concise The method of calling the function is different, and the object this refers to is also different. [Whoever […]