Class语法糖

时间:2023-03-09 05:15:11
Class语法糖

TypeScript源码

class A {
hello() { }
} class B extends A{
welcome() { }
}

TypeScript编译

var __extends = (this && this.__extends) || (function () {
var extendStatics = function (d, b) {
extendStatics = Object.setPrototypeOf ||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
return extendStatics(d, b);
}
return function (d, b) {
extendStatics(d, b);
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
})();
var A = /** @class */ (function () {
function A() {
}
A.prototype.hello = function () {
};
return A;
}());
var B = /** @class */ (function (_super) {
__extends(B, _super);
function B() {
return _super !== null && _super.apply(this, arguments) || this;
}
B.prototype.welcome = function () {
};
return B;
}(A));

Babel源码

lass Auto {
constructor(type, model) {
this.type = type;
this.model = model;
}
static hello() { }
drive() { }
} class Car extends Auto {
constructor(type, model,name) {
super(type, model);
this.name = name;
}
welcome() { }
} let car = new Car('客车','承载式','Cadillac');

Babel编译

var _createClass = function() {
function defineProperties(target, props) {
for(var i = 0; i < props.length; i++) {
var descriptor = props[i];
descriptor.enumerable = descriptor.enumerable || false;
descriptor.configurable = true;
if("value" in descriptor) descriptor.writable = true;
Object.defineProperty(target, descriptor.key, descriptor);
}
}
return function(Constructor, protoProps, staticProps) {
if(protoProps) defineProperties(Constructor.prototype, protoProps);
if(staticProps) defineProperties(Constructor, staticProps);
return Constructor;
};
}(); function _possibleConstructorReturn(self, call) {
if(!self) {
throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
}
return call && (typeof call === "object" || typeof call === "function") ? call : self;
} function _inherits(subClass, superClass) {
if(typeof superClass !== "function" && superClass !== null) {
throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
}
subClass.prototype = Object.create(superClass && superClass.prototype, {
constructor: {
value: subClass,
enumerable: false,
writable: true,
configurable: true
}
});
if(superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass;
} function _classCallCheck(instance, Constructor) {
if(!(instance instanceof Constructor)) {
throw new TypeError("Cannot call a class as a function");
}
}
var Auto = function() {
function Auto(type, model) {
_classCallCheck(this, Auto);
this.type = type;
this.model = model;
}
_createClass(Auto, [{
key: 'drive',
value: function drive() { }
}], [{
key: 'hello',
value: function hello() {}
}]);
return Auto;
}();
var Car = function(_Auto) {
_inherits(Car, _Auto); function Car(type, model, name) {
_classCallCheck(this, Car);
var _this = _possibleConstructorReturn(this, (Car.__proto__ || Object.getPrototypeOf(Car)).call(this,
type, model));
_this.name = name;
return _this;
}
_createClass(Car, [{
key: 'welcome',
value: function welcome() { }
}]);
return Car;
}(Auto); var car = new Car('客车', '承载式', 'Cadillac');