Bold style. With the development of technology, js reverse engineering has become an indispensable technology for crawlers. I just talk about it here, based on my own experience. Do not spray the snake.
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js reverse, you first have to understand the function of it example:
.function per（x，y）{ return x+y；}
For example, this function function he is to declare a function, his name is called per, there are two parameters, x, y. You have to understand the logic of the operation. This function returns the sum of x+y. -
Example of li function closure:
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(function () { var r = 0; return function () {return r += 1;} })
This function is a closure function. If you want to call this closure function, you can assign this function to a variable, and then add a bracket at the end of it. For example
var per=(function () { var r = 0; return function () {return r += 1;} })（）
, if you do not add a registration at the end, it will return a function directly
ƒ () {return counter += 1;}
because you only call it once. If you use it without parentheses, just call the per()() function. The name can be called by adding two brackets -
js timer, this thing is too big and many newbies don’t know how to do it. In fact, we just imitate the webpage to generate data, then I can also fake some functions from the data on the webpage, such as this timer, we define it like this
var setInterval=function（x1,x2）{x1();}
Seeing the timer, first of all, we have to think that one of its parameters is a method, so we only need to find a method for it. There are many methods. The method is dead, but man is alive. -
The basis of js reverse engineering, know how to get these things in flat flow, how to get its execution order.
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At least you have to understand the several loop codes of js.