Description & | alternative usage in javascript _ basic knowledge

This article mainly introduces the alternative usage of & amp; and | in javascript. If you need it, you can refer to it and start to study Titanium, it was found that its official MVC Framework (Alloy) was quite good. At the beginning, it suffered from the lack of good code to learn, and there were few documents, so it had not been studied in detail, later, I found that the official CodeStrong is a very good set of learning code. As long as I read the complete set of code, I believe the use of Alloy will basically be ~

While looking at its source code, it is found that many places use the following usage:

$. Clouds & ($. index. add ($. clouds ));

I didn't quite understand it at the beginning. After all, I usually used a little bit of it. After I got to google, I realized that this method was very convenient and easy to use (in fact, this method is also widely used in jquery's source code ). The following is a reference to the online explanation & | an alternative usage in javascript:
A () & B (): If true is returned after a () is executed, B () is executed and the value of B is returned. If false is returned after a () is executed, then the entire expression returns the value of a (), and B () is not executed;
A () | B (): If true is returned after a () is executed, the entire expression returns the value of a (). B () is not executed. If a () is executed () if false is returned, B () is executed and the value of B () is returned;

& The priority is higher than |

It is quite clear after reading it. Let's look at the specific code:
Alert (1 & 3 | 0) & 4); // Result 4 ①
Alert (1 & 3 | 0 & 4); // result 3 ②
Alert (0 & 3 | 1 & 4); // Result 4 ③

Analysis:

Statement ①: 1 & 3 returns 3 => 3 | 0 returns 3 => 3 & 4 returns 4
Statement ②: Execute 1 & 3 first, return 3, return 0 in execution 0 & 4, and finally compare 3 | 0 returns 3
Statement ③: Execute 0 & 3 first, return 0, return 4 in execution 1 & 4, and finally compare 0 | 4 returns 4
Note: All integers other than 0 are true, and "undefined, null, and null" is false.

Javascript is really flexible !!