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//父类构造函数
function Employee(name, salary) {
//实例属性：姓名
this.name = name;
//实例属性：薪资
this.salary = salary;
}
//通过字面量对象设置父类的原型，给父类添加实例方法
Employee.prototype = {
//由于此处添加实例方法时也是通过修改父类原型处理的，
//所以必须修改父类原型的constructor指向，避免父类实例的constructor属性指向Object函数
constructor: Employee,
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
}
//子类构造函数
function Manager(name, salary, percentage) {
//对象冒充，实现属性继承（name, salary）
Employee.apply(this, [name, salary]);
//实例属性：提成
this.percentage = percentage;
}
//将父类的一个实例设置为子类的原型，实现方法继承
Manager.prototype = new Employee();
//修改子类原型的constructor指向，避免子类实例的constructor属性指向父类的构造函数
Manager.prototype.constructor = Manager;
//给子类添加新的实例方法
Manager.prototype.getSalary = function () {
return this.salary + this.salary * this.percentage;
}
var e = new Employee('jason', 5000);
var m = new Manager('tom', 8000, 0.15);
console.log(e.toString()); //jason's salary is 5000.
console.log(m.toString()); //tom's salary is 9200.
console.log(m instanceof Manager); //true
console.log(m instanceof Employee); //true
console.log(e instanceof Employee); //true
console.log(e instanceof Manager); //false

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//将父类的一个实例设置为子类的原型，实现方法继承
SubClass.prototype = new SuperClass();
//修改子类原型的constructor指向，避免子类实例的constructor属性指向父类的构造函数
SubClass.prototype.constructor = SubClass;
//给子类添加新的实例方法
SubClass.prototype.method1 = function() {
}
SubClass.prototype.method2 = function() {
}
SubClass.prototype.method3 = function() {
}

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//无参无逻辑的父类构造函数
function Employee() {}
Employee.prototype = {
constructor: Employee,
//把构造逻辑搬到init方法中来
init: function (name, salary) {
this.name = name;
this.salary = salary;
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
};
//无参无逻辑的子类构造函数
function Manager() {}
Manager.prototype = new Employee();
Manager.prototype.constructor = Manager;
//把构造逻辑搬到init方法中来
Manager.prototype.init = function (name, salary, percentage) {
//借用父类的init方法，实现属性继承（name, salary）
Employee.prototype.init.apply(this, [name, salary]);
this.percentage = percentage;
};
Manager.prototype.getSalary = function () {
return this.salary + this.salary * this.percentage;
};

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var e = new Employee();
e.init('jason', 5000);
var m = new Manager();
m.init('tom', 8000, 0.15);
console.log(e.toString()); //jason's salary is 5000.
console.log(m.toString()); //tom's salary is 9200.
console.log(m instanceof Manager); //true
console.log(m instanceof Employee); //true
console.log(e instanceof Employee); //true
console.log(e instanceof Manager); //false

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//添加一个全局标识initializing，表示是否正在进行子类的构建和类的继承
var initializing = false;
//可自动调用init方法的父类构造函数
function Employee() {
if (!initializing) {
this.init.apply(this, arguments);
}
}
Employee.prototype = {
constructor: Employee,
//把构造逻辑搬到init方法中来
init: function (name, salary) {
this.name = name;
this.salary = salary;
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
};
//可自动调用init方法的子类构造函数
function Manager() {
if (!initializing) {
this.init.apply(this, arguments);
}
}
//表示开始子类的构建和类的继承
initializing = true;
//此时调用new Emplyee()，并不会调用Employee.prototype.init方法
Manager.prototype = new Employee();
Manager.prototype.constructor = Manager;
//表示结束子类的构建和类的继承，之后调用new Employee或new Manager都会自动调用init实例方法
initializing = false;
//把构造逻辑搬到init方法中来
Manager.prototype.init = function (name, salary, percentage) {
//借用父类的init方法，实现属性继承（name, salary）
Employee.prototype.init.apply(this, [name, salary]);
this.percentage = percentage;
};
Manager.prototype.getSalary = function () {
return this.salary + this.salary * this.percentage;
};

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SubClass.prototype = new SuperClass();

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//用来复制父类原型，由于父类原型上约定只写实例方法，所以复制的时候不必担心引用的问题
var copy = function (source) {
var target = {};
for (var i in source) {
if (source.hasOwnProperty(i)) {
target[i] = source[i];
}
}
return target;
}
function Employee() {
this.init.apply(this, arguments);
}
Employee.prototype = {
constructor: Employee,
init: function (name, salary) {
this.name = name;
this.salary = salary;
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
};
function Manager() {
this.init.apply(this, arguments);
}
//将父类的原型方法复制到子类的原型上
Manager.prototype = copy(Employee.prototype);
//子类还是需要修改constructor指向，因为从父类原型复制出来的对象的constructor还是指向父类的构造函数
Manager.prototype.constructor = Manager;
Manager.prototype.init = function (name, salary, percentage) {
Employee.prototype.init.apply(this, [name, salary]);
this.percentage = percentage;
};
Manager.prototype.getSalary = function () {
return this.salary + this.salary * this.percentage;
};
var e = new Employee('jason', 5000);
var m = new Manager('tom', 8000, 0.15);
console.log(e.toString()); //jason's salary is 5000.
console.log(m.toString()); //tom's salary is 9200.
console.log(m instanceof Manager); //true
console.log(m instanceof Employee); //false
console.log(e instanceof Employee); //true
console.log(e instanceof Manager); //false

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function SuperClass() {}
SuperClass.prototype = {
constructor: SuperClass,
method1: function () {}
}
function SubClass() {
//调用父类构造函数
SuperClass.apply(this);
}
SubClass.prototype = new SuperClass();
SubClass.prototype.constructor = SubClass;
SubClass.prototype.method1 = function () {
//调用父类的实例方法
SuperClass.prototype.method1.apply(this, arguments);
}
SubClass.prototype.method2 = function () {}
SubClass.prototype.method3 = function () {}

每次都得靠apply借用方法来处理。要是能改成如下的调用就好用多了：

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function SubClass() {
//调用父类构造函数
this.base();
}
SubClass.prototype = new SuperClass();
SubClass.prototype.constructor = SubClass;
SubClass.prototype.method1 = function() {
//调用父类的实例方法
this.base();
}

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//用来复制父类原型，由于父类原型上约定只写实例方法，所以复制的时候不必担心引用的问题
var copy = function (source) {
var target = {};
for (var i in source) {
if (source.hasOwnProperty(i)) {
target[i] = source[i];
}
}
return target;
};
function Employee() {
this.init.apply(this, arguments);
}
Employee.prototype = {
constructor: Employee,
init: function (name, salary) {
this.name = name;
this.salary = salary;
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
};
function Manager() {
//必须在每个实例中添加baseProto属性，以便实例内部可以通过这个属性访问到父类的原型
//因为copy函数导致原型链断裂，无法通过原型链访问到父类的原型
this.baseProto = Employee.prototype;
this.init.apply(this, arguments);
}
Manager.prototype = copy(Employee.prototype);
//子类还是需要修改constructor指向，因为从父类原型复制出来的对象的constructor还是指向父类的构造函数
Manager.prototype.constructor = Manager;
Manager.prototype.init = (function (name, func) {
return function () {
//记录实例原有的this.base的值
var old = this.base;
//将实例的this.base指向父类的原型的同名方法
this.base = this.baseProto[name];
//调用子类自身定义的init方法，也就是func参数传递进来的函数
var ret = func.apply(this, arguments);
//还原实例原有的this.base的值
this.base = old;
return ret;
}
})('init', function (name, salary, percentage) {
//通过this.base调用父类的init方法
//这个函数真实的调用位置是var ret = func.apply(this, arguments);
//当调用Manager实例的init方法时，其实不是调用的这个函数
//而是调用上面那个匿名函数里面return的匿名函数
//在return的匿名函数里，先把this.base指向为了父类原型的同名函数，然后在调用func
//func内部再通过调用this.base时，就能调用父类的原型方法。
this.base(name, salary);
this.percentage = percentage;
});
Manager.prototype.getSalary = function () {
return this.salary + this.salary * this.percentage;
};
var e = new Employee('jason', 5000);
var m = new Manager('tom', 8000, 0.15);
console.log(e.toString()); //jason's salary is 5000.
console.log(m.toString()); //tom's salary is 9200.
console.log(m instanceof Manager); //true
console.log(m instanceof Employee); //false
console.log(e instanceof Employee); //true
console.log(e instanceof Manager); //false

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var copy = function (source) {
var target = {};
for (var i in source) {
if (source.hasOwnProperty(i)) {
target[i] = source[i];
}
}
return target;
};
function Employee() {
this.init.apply(this, arguments);
}
//添加一个静态属性
Employee.idCounter = 1;
//添加一个静态方法
Employee.getId = function () {
return Employee.idCounter++;
};
Employee.prototype = {
constructor: Employee,
init: function (name, salary) {
this.name = name;
this.salary = salary;
//调用静态方法
this.id = Employee.getId();
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
};
function Manager() {
this.baseProto = Employee.prototype;
this.init.apply(this, arguments);
}
Manager.prototype = copy(Employee.prototype);
Manager.prototype.constructor = Manager;
Manager.prototype.init = (function (name, func) {
return function () {
var old = this.base;
this.base = this.baseProto[name];
var ret = func.apply(this, arguments);
this.base = old;
return ret;
}
})('init', function (name, salary, percentage) {
this.base(name, salary);
this.percentage = percentage;
});
Manager.prototype.getSalary = function () {
return this.salary + this.salary * this.percentage;
};
var e = new Employee('jason', 5000);
var m = new Manager('tom', 8000, 0.15);
console.log(e.toString()); //jason's salary is 5000.
console.log(m.toString()); //tom's salary is 9200.
console.log(m instanceof Manager); //true
console.log(m instanceof Employee); //false
console.log(e instanceof Employee); //true
console.log(e instanceof Manager); //false
console.log(m.id); //2
console.log(e.id); //1

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//通过调用Class函数构造一个类
var Employee = Class({
//通过instanceMembers指定这个类的实例成员
instanceMembers: {
init: function (name, salary) {
this.name = name;
this.salary = salary;
//调用静态方法
this.id = Employee.getId();
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
},
//通过staticMembers指定这个类的静态成员
//静态方法内部可通过this访问其它静态成员
//在外部可通过Employee.getId这种方式访问到静态成员
staticMembers: {
idCounter: 1,
getId: function () {
return this.idCounter++;
}
}
});
var Manager = Class({
instanceMembers: {
init: function (name, salary, percentage) {
this.base(name, salary);
this.percentage = percentage;
Manager.count++;
},
getSalary: function () {
return this.salary + this.salary * this.percentage;
}
},
//通过extend指定要继承的类
extend: Employee
});

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var Class = (function () {
var hasOwn = Object.prototype.hasOwnProperty;
//用来判断是否为Object的实例
function isObject(o) {
return typeof (o) === 'object';
}
//用来判断是否为Function的实例
function isFunction(f) {
return typeof (f) === 'function';
}
function ClassBuilder(options) {
if (!isObject(options)) {
throw new Error('Class options must be an valid object instance!');
}
var instanceMembers = isObject(options) && options.instanceMembers || {},
staticMembers = isObject(options) && options.staticMembers || {},
extend = isObject(options) && isFunction(options.extend) && options.extend,
prop;
//表示要构建的类的构造函数
function TargetClass() {
if (isFunction(this.init)) {
this.init.apply(this, arguments);
}
}
//添加静态成员，这段代码需在原型设置的前面执行，避免staticMembers中包含prototype属性，覆盖类的原型
for (prop in staticMembers) {
if (hasOwn.call(staticMembers, prop)) {
TargetClass[prop] = staticMembers[prop];
}
}
TargetClass.prototype = instanceMembers;
TargetClass.prototype.constructor = TargetClass;
return TargetClass;
}
return ClassBuilder
})();

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var Employee = Class({
instanceMembers: {
init: function (name, salary) {
this.name = name;
this.salary = salary;
//调用静态方法
this.id = Employee.getId();
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
},
staticMembers: {
idCounter: 1,
getId: function () {
return this.idCounter++;
}
}
});
var e = new Employee('jason', 5000);
console.log(e.toString()); //jason's salary is 5000.
console.log(e.id); //1
console.log(e.constructor === Employee); //true

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var Class = (function () {
var hasOwn = Object.prototype.hasOwnProperty;
//用来判断是否为Object的实例
function isObject(o) {
return typeof (o) === 'object';
}
//用来判断是否为Function的实例
function isFunction(f) {
return typeof (f) === 'function';
}
//简单复制
function copy(source) {
var target = {};
for (var i in source) {
if (hasOwn.call(source, i)) {
target[i] = source[i];
}
}
return target;
}
function ClassBuilder(options) {
if (!isObject(options)) {
throw new Error('Class options must be an valid object instance!');
}
var instanceMembers = isObject(options) && options.instanceMembers || {},
staticMembers = isObject(options) && options.staticMembers || {},
extend = isObject(options) && isFunction(options.extend) && options.extend,
prop;
//表示要构建的类的构造函数
function TargetClass() {
if (extend) {
//如果有要继承的父类
//就在每个实例中添加baseProto属性，以便实例内部可以通过这个属性访问到父类的原型
//因为copy函数导致原型链断裂，无法通过原型链访问到父类的原型
this.baseProto = extend.prototype;
}
if (isFunction(this.init)) {
this.init.apply(this, arguments);
}
}
//添加静态成员，这段代码需在原型设置的前面执行，避免staticMembers中包含prototype属性，覆盖类的原型
for (prop in staticMembers) {
if (hasOwn.call(staticMembers, prop)) {
TargetClass[prop] = staticMembers[prop];
}
}
//如果有要继承的父类，先把父类的实例方法都复制过来
extend && (TargetClass.prototype = copy(extend.prototype));
//添加实例方法
for (prop in instanceMembers) {
if (hasOwn.call(instanceMembers, prop)) {
TargetClass.prototype[prop] = instanceMembers[prop];
}
}
TargetClass.prototype.constructor = TargetClass;
return TargetClass;
}
return ClassBuilder
})();

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var Employee = Class({
instanceMembers: {
init: function (name, salary) {
this.name = name;
this.salary = salary;
//调用静态方法
this.id = Employee.getId();
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
},
staticMembers: {
idCounter: 1,
getId: function () {
return this.idCounter++;
}
}
});
var Manager = Class({
instanceMembers: {
init: function (name, salary, percentage) {
//借用父类的init方法，实现属性继承（name, salary）
Employee.prototype.init.apply(this, [name, salary]);
this.percentage = percentage;
},
getSalary: function () {
return this.salary + this.salary * this.percentage;
}
},
extend: Employee
});
var e = new Employee('jason', 5000);
var m = new Manager('tom', 8000, 0.15);
console.log(e.toString()); //jason's salary is 5000.
console.log(m.toString()); //tom's salary is 9200.
console.log(e.constructor === Employee); //true
console.log(m.constructor === Manager); //true
console.log(e.id); //1
console.log(m.id); //2

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var Class = (function () {
var hasOwn = Object.prototype.hasOwnProperty;
//用来判断是否为Object的实例
function isObject(o) {
return typeof (o) === 'object';
}
//用来判断是否为Function的实例
function isFunction(f) {
return typeof (f) === 'function';
}
//简单复制
function copy(source) {
var target = {};
for (var i in source) {
if (hasOwn.call(source, i)) {
target[i] = source[i];
}
}
return target;
}
function ClassBuilder(options) {
if (!isObject(options)) {
throw new Error('Class options must be an valid object instance!');
}
var instanceMembers = isObject(options) && options.instanceMembers || {},
staticMembers = isObject(options) && options.staticMembers || {},
extend = isObject(options) && isFunction(options.extend) && options.extend,
prop;
//表示要构建的类的构造函数
function TargetClass() {
if (extend) {
//如果有要继承的父类
//就在每个实例中添加baseProto属性，以便实例内部可以通过这个属性访问到父类的原型
//因为copy函数导致原型链断裂，无法通过原型链访问到父类的原型
this.baseProto = extend.prototype;
}
if (isFunction(this.init)) {
this.init.apply(this, arguments);
}
}
//添加静态成员，这段代码需在原型设置的前面执行，避免staticMembers中包含prototype属性，覆盖类的原型
for (prop in staticMembers) {
if (hasOwn.call(staticMembers, prop)) {
TargetClass[prop] = staticMembers[prop];
}
}
//如果有要继承的父类，先把父类的实例方法都复制过来
extend && (TargetClass.prototype = copy(extend.prototype));
//添加实例方法
for (prop in instanceMembers) {
if (hasOwn.call(instanceMembers, prop)) {
//如果有要继承的父类，且在父类的原型上存在当前实例方法同名的方法
if (extend && isFunction(instanceMembers[prop]) && isFunction(extend.prototype[prop])) {
TargetClass.prototype[prop] = (function (name, func) {
return function () {
//记录实例原有的this.base的值
var old = this.base;
//将实例的this.base指向父类的原型的同名方法
this.base = this.baseProto[name];
//调用子类自身定义的实例方法，也就是func参数传递进来的函数
var ret = func.apply(this, arguments);
//还原实例原有的this.base的值
this.base = old;
return ret;
}
})(prop, instanceMembers[prop]);
} else {
TargetClass.prototype[prop] = instanceMembers[prop];
}
}
}
TargetClass.prototype.constructor = TargetClass;
return TargetClass;
}
return ClassBuilder
})();

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var Employee = Class({
instanceMembers: {
init: function (name, salary) {
this.name = name;
this.salary = salary;
//调用静态方法
this.id = Employee.getId();
},
getName: function () {
return this.name;
},
getSalary: function () {
return this.salary;
},
toString: function () {
return this.name + '\'s salary is ' + this.getSalary() + '.';
}
},
staticMembers: {
idCounter: 1,
getId: function () {
return this.idCounter++;
}
}
});
var Manager = Class({
instanceMembers: {
init: function (name, salary, percentage) {
//通过this.base调用父类的构造方法
this.base(name, salary);
this.percentage = percentage;
},
getSalary: function () {
return this.base() + this.salary * this.percentage;
}
},
extend: Employee
});
var e = new Employee('jason', 5000);
var m = new Manager('tom', 8000, 0.15);
console.log(e.toString()); //jason's salary is 5000.
console.log(m.toString()); //tom's salary is 9200.
console.log(e.constructor === Employee); //true
console.log(m.constructor === Manager); //true
console.log(e.id); //1
console.log(m.id); //2