javascript防止对象被修改

对象类型/操作	增加	删除	修改
初始对象	T	T	T
不可扩展对象	F	T	T
封闭对象	F	F	T
冷冻对象	F	F	F

一、不可扩展对象

        window.onload = function(){
            var test = {
                name: 'tom',
                father: 'bob'
            }

            /*
            * 初始对象
            */
            console.log(Object.isExtensible(test));//初始可扩展
            console.log(Object.isSealed(test));//初始不是封闭
            console.log(Object.isFrozen(test));//初始不冻结
            test.age = '29';//可以增
            console.log(test.age);
            delete test.age;//可以删
            console.log(test.age);
            test.name = 'alice';//可以改
            console.log(test.name);
            console.log("=======================================")

            /*
            *  不可扩展对象
            */
            Object.preventExtensions(test); 
            console.log(Object.isExtensible(test));//不可扩展
            test.age = '29';//不可增
            console.log(test.age);
            delete test.father;//可以删
            console.log(test.father);
            test.name = 'happy';//可以改
            console.log(test.name);
            console.log("----------------------------------------")

            /*
            *  封闭对象
            */
            // Object.seal(test); 
            // console.log(Object.isExtensible(test));//不可扩展
            // console.log(Object.isSealed(test)); //封闭
            // test.age = '29';//不可增
            // console.log(test.age);
            // delete test.name;//不可删
            // console.log(test.name);
            // test.name = 'happy';//可以改
            // console.log(test.name);
            // console.log("----------------------------------------")

            /*
            *  冻结对象
            */
            // Object.freeze(test); 
            // console.log(Object.isExtensible(test));//不可扩展
            // console.log(Object.isSealed(test)); //封闭
            // console.log(Object.isFrozen(test)); //冻结
            // test.age = '29';//不可增
            // console.log(test.age);
            // delete test.name;//不可删
            // console.log(test.name);
            // test.name = 'happy';//不可改
            // console.log(test.name);
            // console.log("----------------------------------------")
        }

二、密封的对象

        window.onload = function(){
            var test = {
                name: 'tom',
                father: 'bob'
            }

            /*
            * 初始对象
            */
            console.log(Object.isExtensible(test));//初始可扩展
            console.log(Object.isSealed(test));//初始不是封闭
            console.log(Object.isFrozen(test));//初始不冻结
            test.age = '29';//可以增
            console.log(test.age);
            delete test.age;//可以删
            console.log(test.age);
            test.name = 'alice';//可以改
            console.log(test.name);
            console.log("=======================================")

            /*
            *  不可扩展对象
            */
            // Object.preventExtensions(test); 
            // console.log(Object.isExtensible(test));//不可扩展
            // test.age = '29';//不可增
            // console.log(test.age);
            // delete test.father;//可以删
            // console.log(test.father);
            // test.name = 'happy';//可以改
            // console.log(test.name);
            // console.log("----------------------------------------")

            /*
            *  封闭对象
            */
            Object.seal(test); 
            console.log(Object.isExtensible(test));//不可扩展
            console.log(Object.isSealed(test)); //封闭
            test.age = '29';//不可增
            console.log(test.age);
            delete test.name;//不可删
            console.log(test.name);
            test.name = 'happy';//可以改
            console.log(test.name);
            console.log("----------------------------------------")

            /*
            *  冻结对象
            */
            // Object.freeze(test); 
            // console.log(Object.isExtensible(test));//不可扩展
            // console.log(Object.isSealed(test)); //封闭
            // console.log(Object.isFrozen(test)); //冻结
            // test.age = '29';//不可增
            // console.log(test.age);
            // delete test.name;//不可删
            // console.log(test.name);
            // test.name = 'happy';//不可改
            // console.log(test.name);
            // console.log("----------------------------------------")
        }

三、冻结的对象

        window.onload = function(){
            var test = {
                name: 'tom',
                father: 'bob'
            }

            /*
            * 初始对象
            */
            console.log(Object.isExtensible(test));//初始可扩展
            console.log(Object.isSealed(test));//初始不是封闭
            console.log(Object.isFrozen(test));//初始不冻结
            test.age = '29';//可以增
            console.log(test.age);
            delete test.age;//可以删
            console.log(test.age);
            test.name = 'alice';//可以改
            console.log(test.name);
            console.log("=======================================")

            /*
            *  不可扩展对象
            */
            // Object.preventExtensions(test); 
            // console.log(Object.isExtensible(test));//不可扩展
            // test.age = '29';//不可增
            // console.log(test.age);
            // delete test.father;//可以删
            // console.log(test.father);
            // test.name = 'happy';//可以改
            // console.log(test.name);
            // console.log("----------------------------------------")

            /*
            *  封闭对象
            */
            // Object.seal(test); 
            // console.log(Object.isExtensible(test));//不可扩展
            // console.log(Object.isSealed(test)); //封闭
            // test.age = '29';//不可增
            // console.log(test.age);
            // delete test.name;//不可删
            // console.log(test.name);
            // test.name = 'happy';//可以改
            // console.log(test.name);
            // console.log("----------------------------------------")

            /*
            *  冻结对象
            */
            Object.freeze(test); 
            console.log(Object.isExtensible(test));//不可扩展
            console.log(Object.isSealed(test)); //封闭
            console.log(Object.isFrozen(test)); //冻结
            test.age = '29';//不可增
            console.log(test.age);
            delete test.name;//不可删
            console.log(test.name);
            test.name = 'happy';//不可改
            console.log(test.name);
            console.log("----------------------------------------")

四、深冻结