How to use asynchronous functions? Summarize the usage of asynchronous function examples

Study a small question today: How to get the return value of a JavaScript asynchronous function? 1. Wrong attempt When I didn’t enter the industry that year, my initial attempt was: <script> function getSomething() { var r = 0; setTimeout(function() { r = 2; }, 10); return r; } function compute() { var x = getSomething(); alert(x * 2); } compute(); </script>2. The callback function pops up is not 4, but

1. How to get the return value of JavaScript asynchronous function

Introduction: Let’s study a small question today: How to get the return value of a JavaScript asynchronous function? 1. Wrong attempt When I was not in the industry, my initial attempt was: <script>function getSomething() { var r = 0; setTimeout(function() { r = 2; }, 10); return r;}function compute( ) { var x = getSomething(); alert(x * 2);}compute</script>

2. Detailed introduction to JavaScript asynchronous function development process code examples

Introduction: For most JavaScript developers, the async function is a new thing, and its development has gone through a long period of time. journey. Therefore, this article attempts to sort out and summarize the development history of JavaScript asynchronous functions: Not long ago, we could only write callback functions to implement asynchronous functions, and then the Promise/A+ standard came out. After that, generator functions appeared, and the future is obviously async functions. of. Now let us review the development of JavaScript asynchronous functions over the years. Callback function Callbacks It seems that everything should start with the callback function. Different..

3. Detailed introduction to using bind() method in JavaScript to make the code cleaner

Introduction: A few weeks ago, I wrote about how to turn off the effects of calling an async function in a loop and several ways to deal with this problem. In my recent coding, I discovered an easier way. In the process, it eliminates anonymous functions and removes the linting error, "Don't write functions in loops". You see, I've been experimenting with bind() in JavaScript. It turns out that we can use bind in a number of situations, including dealing with the closure problem I mentioned a few weeks ago. What is bind()? The bind function was recently added to the JavaScript specification..

4. JavaScript Advanced Series - Function Declarations and Expressions

#Introduction: Functions are first-class objects in JavaScript, which means they can be passed around like other values. A common usage is to pass an anonymous function as a callback function into an asynchronous function.

5. JavaScript Asynchronous Calling Framework (Part 4 - Chained Calling)_javascript Skills

Introduction: We have A simple asynchronous calling framework has been implemented, but there are still some shortcomings, that is, asynchronous functions that are executed sequentially need to be declared in a nested manner.

6. A concise summary of common functions of nodejs file operation module FS (File System)_node.js

Introduction : This article mainly introduces a concise summary of the commonly used functions of the nodejs file operation module FS (File System). It introduces most of the asynchronous functions of the FS module and uses Chinese annotations. It is convenient to use now. Friends who need it can Refer to the following

7. Javascript Study Notes - Function (1): Function Declaration and Function Expression_Basic Knowledge

Introduction: Function is a first-class object in Javascript, which means that functions can be passed like other values. One of the most common uses is to pass an anonymous function as a callback function to another asynchronous function.

8. Use Promise to encapsulate asynchronous functions in NodeJS_node.js

Introduction: This article mainly Introduced the use of Promise in NodeJS to encapsulate asynchronous functions, and the use of a unified chain API to get rid of the nightmare of multiple callbacks. It is a very practical little skill. I hope friends will like it

##9 . Talk about the development history of JavaScript asynchronous functions_javascript skills

Introduction: For most JavaScript developers, async functions are still a new thing, and their development experience A long journey. This article will summarize the development history of JavaScript asynchronous functions and indicate that async functions will become the main way to implement asynchronous functions in the future.

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