Bit Operations - Why ~8=-9, ~-8=7 in javascript?

After studying the relevant information on bitwise operations in JavaScript, I really don’t understand the inverted bitwise operation. I don’t understand why the inverted bitwise operation is not the maximum number - the current value, but ~8=-9, ~-8=7?

滿天的星座 2017-05-18 10:59:22 0  5  1008

In the practical PHP imitation iQiyi tutorial, the solution to the problem that the 5-9 permission menu cannot be opened

In the practical PHP imitation iQiyi tutorial, the 5-9 permission menu does not load ‘children’ and the permission menu cannot be opened. Please give me some advice.

絔 2019-08-13 17:06:34 0  2  1390

JavaScript development of Baidu map

JavaScript development of Baidu Map 1. Complete the content and mark different icons according to different business types (A, B, C, D, E) (completed) 2. Click the marking point to pop up the title in the markerArr array respectively, yetai and other content can currently pop up The content of the m...

九日 2020-05-13 14:03:06 1  5  1242

javascript - csp issues when developing Google plug-ins with vue

I want to use vuejs and some component libraries to develop a Google plug-in, but due to the content security policy (csp), JavaScript features such as eval() new Function() cannot be used, so vue cannot be used normally. The official document only vaguely talks about this part. For a moment.

typecho 2017-07-05 11:02:25 0  1  922

javascript - I have a question about setting the page title after opening a pdf file on a web page?

I need to open a pdf file in a web page. I use the original method window.open(myurl) in javascript to open the pdf. Everything else is fine, except that the title of the page displays the information in the url. I want to set my own title but it never works. The effect is that there are some method...

为情所困 2017-05-19 10:15:26 0  1  454

javascript - Is there a front-end framework suitable for developing mobile Html5 web games?

I do PHP, and currently I only use simple javaScript and JQuery, and I have never used a front-end framework. Is there a front-end framework suitable for developing mobile Html5 web games? Just some simple mini-games, such as Snake, Tetris, and masturbation, which may need appropriate beautification...

仅有的幸福 2017-05-31 10:42:02 0  7  1333

Preview of the teaching course on September 11, 2018: Introduction to JavaScript, detailed explanation of data types and objects, arrays and process control

1. Teaching Topic: Introduction to JavaScript: Data Types, Function Objects and Array Process Control and Practical Cases. For more detailed explanations of JavaScript knowledge points, please pay attention to tonight’s live broadcast course! Lecturer: Peter Zhu 2. Teaching time: 20:00 ~ 22:00 pm 3....

藏色散人 2018-09-11 10:10:23 0  0  1275

MySQL WHERE clause usage

MySQL I'm trying to get Category_id values ​​between 9 and the largest category id without using the Max function (using a subquery). I tried the MySQL query given below. It works for the latter part, i.e. it gives category_id up to the maximum category_id. However, it gives all category IDs (1) fro...

P粉403804844 2023-09-09 20:28:44 0  1  566

It's so uncomfortable, the chapter titles are inconsistent with the content.

JavaScript Dark Horse Programmer, the titles of 7-8 and 7-9 are the same, but the content is different.

WeiZhang 2018-05-02 14:38:59 0  0  1023

javascript - webstorm11 cannot be opened

Webstrom11 has been reinstalled, and the configuration and data inside have been deleted, but it just can’t be opened and no error has been reported!

黄舟 2017-05-19 10:45:50 0  1  449

How to randomize the order of an array?

I want to shuffle an array of elements in JavaScript like this: [0,3,3]->[3,0,3][9,3,6,0,6]->[0,3,6, 9,6][3,3,6,0,6]->[0,3,6,3,6]

P粉512526720 2023-10-11 18:42:00 0  2  581