Prototype inheritance of javascript

Please refer to the source code: Copy codeThe Code is as follows: function clone (o ){
Var F = function (){};
F. prototype = o;
Return new F ();
}

First, let's take a look at the original type inheritance of ext (starting with row 4.1 of 1896.Copy codeCode: var TemplateClass = function (){};
Var ExtObject = Ext. Object = {
Chain: function (object ){
TemplateClass. prototype = object;
Var result = new TemplateClass ();
TemplateClass. prototype = null;
Return result;
}
}

The prototype of the object is cleared here.
Let's take a look at jquery's inheritance.Copy codeThe Code is as follows: var jQuery = function (selector, context ){
Return new jQuery. fn. init (selector, context, rootjQuery );
};
-----------------------
JQuery. fn = jQuery. prototype = {
Constructor: jQuery,
Init: function (selector, context, rootjQuery ){
-----------------------
}
}
-------------------
JQuery. fn. init. prototype = jQuery. fn;

Jquery has a relatively high level of play. It can be done with jQuery. fn. init, but the idea is the same.
Situ's mass also have similar inheritance. Lines 17th in lang_fix.js:Copy codeThe Code is as follows: create: function (o ){
If (arguments. length> 1 ){
$. Log ("Object. create implementation only accepts the first parameter .")
}
Function F (){}
F. prototype = o;
Return new F ();
}

I checked es5's official website and found its compatible patch:Copy codeThe Code is as follows: // ES5 15.2.3.5
// Http://es5.github.com/#x15.2.3.5
If (! Object. create ){
Object. create = function create (prototype, properties ){
Var object;
If (prototype = null ){
Object = {"_ proto _": null };
} Else {
If (typeof prototype! = "Object "){
Throw new TypeError ("typeof prototype [" + (typeof prototype) + "]! = 'Object '");
}
Var Type = function (){};
Type. prototype = prototype;
Object = new Type ();
// IE has no built-in implementation of 'object. getPrototypeOf'
// Neither '_ proto _', but this manually setting '_ proto _' will
// Guarantee that 'object. getPrototypeOf 'will work as expected
// Objects created using 'object. create'
Object. _ proto _ = prototype;
}
If (properties! = Void 0 ){
Object. defineProperties (object, properties );
}
Return object;
};
}

The above code is more comprehensive, but the patch of Object. defineProperties needs to be introduced separately, and the source code is more.Copy codeThe Code is as follows: // ES5 15.2.3.6
// Http://es5.github.com/#x15.2.3.6
// Patch for WebKit and IE8 standard mode
// Designed by hax // Related issue: https://github.com/kriskowal/es5-shim/issues#issue/5
// IE8 Reference:
// Http://msdn.microsoft.com/en-us/library/dd282900.aspx
// Http://msdn.microsoft.com/en-us/library/dd229916.aspx
// WebKit Bugs:
// Https://bugs.webkit.org/show_bug.cgi? Id = 36423
Function doesDefinePropertyWork (object ){
Try {
Object. defineProperty (object, "sentinel ",{});
Return "sentinel" in object;
} Catch (exception ){
// Returns falsy
}
}
// Check whether defineProperty works if it's given. Otherwise,
// Shim partially.
If (Object. defineProperty ){
Var definePropertyWorksOnObject = doesDefinePropertyWork ({});
Var definePropertyWorksOnDom = typeof document = "undefined" |
DoesDefinePropertyWork (document. createElement ("div "));
If (! DefinePropertyWorksOnObject |! DefinePropertyWorksOnDom ){
Var definePropertyFallback = Object. defineProperty;
}
}
If (! Object. defineProperty | definePropertyFallback ){
Var ERR_NON_OBJECT_DESCRIPTOR = "Property description must be an object :";
Var ERR_NON_OBJECT_TARGET = "Object. defineProperty called on non-object :"
Var ERR_ACCESSORS_NOT_SUPPORTED = "getters & setters can not be defined" +
"On this javascript engine ";
Object. defineProperty = function defineProperty (object, property, descriptor ){
If (typeof object! = "Object" & typeof object! = "Function") | object = null ){
Throw new TypeError (ERR_NON_OBJECT_TARGET + object );
}
If (typeof descriptor! = "Object" & typeof descriptor! = "Function") | descriptor === null ){
Throw new TypeError (ERR_NON_OBJECT_DESCRIPTOR + descriptor );
}
// Make a valiant attempt to use the real defineProperty
// For I8's DOM elements.
If (definePropertyFallback ){
Try {
Return definePropertyFallback. call (Object, object, property, descriptor );
} Catch (exception ){
// Try the shim if the real one doesn't work
}
}
// If it's a data property.
If (owns (descriptor, "value ")){
// Fail silently if "writable", "enumerable", or "retriable"
// Are requested but not supported
/*
// Alternate approach:
If (// can't implement these features; allow false but not true
! (Owns (descriptor, "writable ")? Descriptor. writable: true) |
! (Owns (descriptor, "enumerable ")? Descriptor. enumerable: true) |
! (Owns (descriptor, "resumable ")? Descriptor. retriable: true)
)
Throw new RangeError (
"This implementation of Object. defineProperty does not" +
"Support retriable, enumerable, or writable ."
);
*/
If (supportsAccessors & (lookupGetter (object, property) |
LookupSetter (object, property )))
{
// As accessors are supported only on engines implementing
// '_ Proto _' we can safely override '_ proto _' while defining
// A property to make sure that we don't hit an inherited
// Accessor.
Var prototype = object. _ proto __;
Object. _ proto _ = prototypeOfObject;
// Deleting a property anyway since getter/setter may be
// Defined on object itself.
Delete object [property];
Object [property] = descriptor. value;
// Setting original '_ proto _ 'back now.
Object. _ proto _ = prototype;
} Else {
Object [property] = descriptor. value;
}
} Else {
If (! SupportsAccessors ){
Throw new TypeError (ERR_ACCESSORS_NOT_SUPPORTED );
}
// If we got that far then getters and setters can be defined !!
If (owns (descriptor, "get ")){
DefineGetter (object, property, descriptor. get );
}
If (owns (descriptor, "set ")){
DefineSetter (object, property, descriptor. set );
}
}
Return object;
};
}
// ES5 15.2.3.7
// Http://es5.github.com/#x15.2.3.7
If (! Object. defineProperties ){
Object. defineProperties = function defineProperties (object, properties ){
For (var property in properties ){
If (owns (properties, property) & property! = "_ Proto __"){
Object. defineProperty (object, property, properties [property]);
}
}
Return object;
};
}

EcmaScript6 class inheritance.Copy codeThe Code is as follows: class module extends Base {
Constructor (){
}
}

The more you play, the more you like java, but es6 is not supported by many browsers.
The recommended statement is as follows:Copy codeThe Code is as follows: if (! Object. create ){
Object. create = function create (o ){
Var F = function (){};
F. prototype = o;
Var result = new F ();
F. prototype = null;
Return result;
}
}