This: Indicates that the current context object is an HTML object that can invoke properties owned by an HTML object, method
$ (this), which represents the context object that is a jquery context object that can invoke the methods and property values of jquery.
The Each:jquery traversal function executes the function for each matching element. You can traverse one-dimensional arrays, multidimensional arrays, DOM, JSON, and so on.
The find () method gets the descendants of each element in the current element collection, filtered by a selector, JQuery object, or element. (not normal DOM objects are objects that jquery encapsulates later)
jquery Dom element method dom contains attribute method
$ ("#div"). each (function () {})
The $ indicator represents jquery. The function is to find and select elements in the HTML document according to the parameters in the (), one function is the substitution of getElementById, but () can not only be an ID, but also a variety of selectors.
Console.log Browser background output related information terminal log indicates a method output log. Ability to output variables, functions, arrays, objects, etc.