遍历js object

obj.js

// 遍历可枚举的自身属性 Ojbect.keys
(function () {
    var propertys = Object.keys(window);
    alert(propertys.length);         //3
    alert(propertys.join("\n"));     //window,document,InstallTrigger,除了最后一个是火狐私有的属性,原来window对象只有两个可枚举的自身属性.window属性指向window对象自身,一般没什么用.
})();

// 遍历所有的自身属性
(function () {
    var propertys = Object.getOwnPropertyNames(window);
    alert(propertys.length);       //72
    alert(propertys.join("\n"));   //Object,Function,eval等等
})();

// 遍历可枚举的自身属性和继承属性
(function () {
    var getEnumPropertyNames = function (obj) {
        var props = [];
        for (prop in obj) {
            props.push(prop);
        }
        return props;
    }
    var propertys = getEnumPropertyNames(window);
    alert(propertys.length);       //185
    alert(propertys.join("\n"));   //addEventListener,onload等等
})();

// 遍历所有的自身属性和继承属性
(function () {
    var getAllPropertyNames = function (obj) {
        var props = [];
        do {
            props = props.concat(Object.getOwnPropertyNames(obj));
        } while (obj = Object.getPrototypeOf(obj));
        return props;
    }
    var propertys = getAllPropertyNames(window);
    alert(propertys.length);          //276
    alert(propertys.join("\n"));      //toString等
})();