《JavaScript高级程序设计2》学习笔记——匿名函数

function createComparisionFunction(prototypeName) {
    return function(object1, object2) {
        var value1 = object1[prototypeName];
        var value2 = object2[prototypeName];
        if(value1 < value2) {
            return -1;
        } else if(value1 > value2) {
            return 1;
        } else {
            return 0;
        }
    }
}

function createFunctions() {
    var result = new Array();
    for(var i=0; i<10; i++) {
        result[i] = function() {
            return i;
        };
    }
    return result;
}
function createFunctions() {
    var result = new Array();
    for(var i=0; i<10; i++) {
        result[i] = function(num) {
            return function() {
                return num;
            }
        }(i);
    }
    return result;
}
var funcs = createFunctions();
for(var i=0; i<funcs.length; i++) {
    document.write(funcs[i]() + '<br />');
}

var name = "The Window";
var obj = {
    name : "My Object",
    getName : function() {
        return function() {
            return this.name;
        }
    }
}
var obj2 = {
    name : "My Object",
    getName : function() {
        var that = this;
        return function() {
            return that.name;
        }
    }
}
alert(obj.getName()());//The Window
alert(obj2.getName()());//My Object

function assignHandler() {//内存泄露
    var element = document.getElementById("someElement");
    element.onclick = function() {
        alert(element.id);
    }
}
function assignHanndler2() {
    var element = document.getElementById("someElement");
    var id = element.id;
    element.onclick = function() {
        alert(id);
    }
    element = null;
}

(function() {
    var name = '';
    Person = function(value) {//全局变量
        name = value;
    }
    Person.prototype.getName = function() {
        return name;
    }
    Person.prototype.setName = function(value) {
        return name = value;
    }
})();
var person = new Person("demo");
alert(person.getName());//demo
person.setName("chemdemo");
alert(person.getName());//chemdemo
var person2 = new Person("Demo Yang");
alert(person2.getName());//Demo Yang

var singleton = function() {
    var privateVariable = 10;
    function privateFunction() {
        return false;
    }
    return {
        publicProperty : true,
        publicMethod : function() {
            privateVariable++;
            return publicMethod();
        }
    }
}();

function BaseComponent() {};
function otherCompenent() {};
var application = function() {
    var components = new Array();
    components.push(new BaseComponent());
    return {
        getComponentCount : function() {
            return components.legth;
        },
        registerComponent : function(component) {
            if(typeof component == "object") {
                components.push(component);
            }
        }
    }
}();
application.registerComponent(new otherCompenent());
alert(application.getComponentCount());

var singleton = function() {
    //私有变量和私有函数
    var privateVariable = 10;
    function privateMethod() {
        return false;
    }
    //创建对象
    var object = new CustomType();
    //添加特权/公有属性和方法
    object.publicProperty = true;
    object.publicProperty = function() {
        privateVariable++;
        return privateMethod();
    }
}

function BaseComponent() {};
function otherCompenent() {};
var application = function() {
    //私有变量和函数
    var components = new Array();
    //初始化
    components.push(new BaseComponent());
    //创建application的一个局部副本
    var app = new BaseComponent();
    //公共接口
    app.getComponentCount = function() {
        return components.length;
    };
    app.registerComponent = function(component) {
        if(typeof component == "object") {
            components.push(component);
        }
    };
    //返回这个副本
    return app;
}