1. 写出构造函数模式、混合模式、模块模式、工厂模式、单例模式、发布订阅模式的范例
<script>
<!-- 模块模式 -->
<!-- 由于函数作用域无法获取内部变量，故进行包装 -->
var Person = (function(){
var name = 'poi';
function sayName() {
console.log(name);
}
return {
name: name,
sayName: sayName
}
})()
<!---构造函数模式 -->
function Person(name, age) {
this.name = name;
this.age = age;
}
Person.prototype.sayName = function(){
return this.name;
};
var student = new Person("poi", 30);
console.log(student);
<!-- 混合模式(继承) -->
var Person = function(name, age) {
this.name = name;
this.age = age;
};
Person.prototype.sayName = function(){
console.log(this.name);
};
var Student = function(name, age, score) {
Person.call(this, name, age)
this.score = score;
};
Student.prototype = create(Person.prototype);
function create(parentObj){
function F(){};
F.prototype = parentObj;
return new F();
};
Student.prototype.sayscore = function(){
console.log(this.score);
}
var student = new Student("poi", 28, 29);
console.log(student);
<!-- 工厂模式 -->
function createPerson(opts){
var person = {
name: opts.name || 'poi'
};
person.sayName = function() {
console.log(this.name);
}
return person;
}
var p1 = createPerson({name:'poi'});
var p2 = createPerson({name: 'yamato'});
<!-- 单例模式- -->
var Car = (function(){
var instance;
function init() {
var speed = 0;
return {
getSpeed: function(){
return speed;
},
setSpeed: function(s){
speed = s;
}
};
}
return {
create: function() {
if(!instance) {
instance = init();
}
return instance;
}
};
})();
var car1 = Car.create();
var car2 = Car.create();
car1 === car2;
<!--发布订阅模式 -->
var Event = (function() {
var events = {};
function on(evt, handler) {
events[evt] = events[evt] || [];
events[evt].push({
handler: handler
});
}
function fire(evt, args) {
if(!events[evt]){
return;
}
for(var i=0; i<events[evt].length; i++){
events[evt][i].handler(args);
}
}
function off(evt) {
delete events[evt];
}
return {
on: on,
fire: fire,
off: off
}
}());
Event.on('change', function(val){
console.log('change... now val is ' + val);
});
Event.fire('change', '饥人谷'); //change... now val is 饥人谷
Event.off('change');
</script>
2. 使用发布订阅模式写一个事件管理器，可以实现如下方式调用
<!--发布订阅模式 -->
var Event = (function() {
var events = {};
function on(evt, handler) {
events[evt] = events[evt] || [];
events[evt].push({
handler: handler
});
}
function fire(evt, args) {
if(!events[evt]){
return;
}
for(var i=0; i<events[evt].length; i++){
events[evt][i].handler(args);
}
}
function off(evt) {
delete events[evt];
}
return {
on: on,
fire: fire,
off: off
}
}());
Event.on('change', function(val){
console.log('change... now val is ' + val);
});
Event.fire('change', '饥人谷'); //change... now val is 饥人谷
Event.off('change');
</script>
