$().find().css()
$().hide().html('....').hide().

var aQuery = function(selector, context) {//构造函数
}
aQuery.prototype = {//原型name:function(){},age:function(){}
}var a = new aQuery();a.name();

$().ready()
$().noConflict()

var aQuery = function(selector, context) {return new aQuery();
}
aQuery.prototype = {name:function(){},age:function(){}
}

var aQuery = function(selector, context) {return  aQuery.prototype.init();
}
aQuery.prototype = {init:function(){return this;}name:function(){},age:function(){}
}

var aQuery = function(selector, context) {return  aQuery.prototype.init();
}
aQuery.prototype = {init: function() {this.age = 18return this;},name: function() {},age: 20
}aQuery().age  //18

jQuery = function( selector, context ) {// The jQuery object is actually just the init constructor 'enhanced'return new jQuery.fn.init( selector, context, rootjQuery );},

var aQuery = function(selector, context) {return  new aQuery.prototype.init();
}
aQuery.prototype = {init: function() {this.age = 18return this;},name: function() {},age: 20
}//Uncaught TypeError: Object [object Object] has no method 'name'
console.log(aQuery().name())

// Give the init function the jQuery prototype for later instantiation
jQuery.fn.init.prototype = jQuery.fn;

var aQuery = function(selector, context) {return  new aQuery.prototype.init();
}
aQuery.prototype = {init: function() {return this;},name: function() {return this.age},age: 20
}aQuery.prototype.init.prototype = aQuery.prototype;console.log(aQuery().name()) //20

aQuery().init().name()分解
a = aQuery();
a.init()
a.name()

aQuery.prototype = {init: function() {return this;},name: function() {return this}
}

aQuery.init().name()

jQuery.extend = jQuery.fn.extend = function() {

jQuery.extend 对jQuery本身的属性和方法进行了扩展jQuery.fn.extend 对jQuery.fn的属性和方法进行了扩展

jQuery.extend = jQuery.fn.extend = function() {var src, copyIsArray, copy, name, options, clone,target = arguments[0] || {},    // 常见用法 jQuery.extend( obj1, obj2 )，此时，target为arguments[0]i = 1,length = arguments.length,deep = false;// Handle a deep copy situationif ( typeof target === "boolean" ) {    // 如果第一个参数为true，即 jQuery.extend( true, obj1, obj2 ); 的情况deep = target;  // 此时target是truetarget = arguments[1] || {};    // target改为 obj1// skip the boolean and the targeti = 2;}// Handle case when target is a string or something (possible in deep copy)if ( typeof target !== "object" && !jQuery.isFunction(target) ) {  // 处理奇怪的情况，比如 jQuery.extend( 'hello' , {nick: 'casper})~~target = {};}// extend jQuery itself if only one argument is passedif ( length === i ) {   // 处理这种情况 jQuery.extend(obj)，或 jQuery.fn.extend( obj )target = this;  // jQuery.extend时，this指的是jQuery；jQuery.fn.extend时，this指的是jQuery.fn--i;}for ( ; i < length; i++ ) {// Only deal with non-null/undefined valuesif ( (options = arguments[ i ]) != null ) { // 比如 jQuery.extend( obj1, obj2, obj3, ojb4 )，options则为 obj2、obj3...// Extend the base objectfor ( name in options ) {src = target[ name ];copy = options[ name ];// Prevent never-ending loopif ( target === copy ) {    // 防止自引用，不赘述continue;}// Recurse if we're merging plain objects or arrays// 如果是深拷贝，且被拷贝的属性值本身是个对象if ( deep && copy && ( jQuery.isPlainObject(copy) || (copyIsArray = jQuery.isArray(copy)) ) ) {if ( copyIsArray ) {    // 被拷贝的属性值是个数组copyIsArray = false;clone = src && jQuery.isArray(src) ? src : [];} else {    被拷贝的属性值是个plainObject，比如{ nick: 'casper' }clone = src && jQuery.isPlainObject(src) ? src : {};}// Never move original objects, clone themtarget[ name ] = jQuery.extend( deep, clone, copy );  // 递归~// Don't bring in undefined values} else if ( copy !== undefined ) {  // 浅拷贝，且属性值不为undefinedtarget[ name ] = copy;}}}}// Return the modified objectreturn target;