Prototype chain in jquery

Question

var jQuery = function(global, factory) {
    return new jQuery.fn.init();
}

jQuery.fn = jQuery.prototype = {
    constructor: jQuery,
    init: function() {
        this.jquery = 3;
        return this;
    },
    each: function() {
        console.log('each');
        return this;
    }
}

jQuery.fn.init.prototype = jQuery.fn;

// init构造函数
jQuery().each().each()

The above is a piece of jQuery source code. My question is why the second each function in the last line of the code can still be executed

Answer 1

This in the prototype points to the instance object, return this in each to return this object, thereby realizing chain calls

Answer 2

Two eachs have the same effect as one each, and the objects are all jQuery

Answer 3

Because what you are returning is this, let alone two, 10 will do too

Answer 4

Chain programming

return this