localStorage存值取值以及存取JSON,以及基于html5 localStorage的购物车

localStorage.setItem("key","value");//存储变量名为key，值为value的变量 localStorage.key = "value"//存储变量名为key，值为value的变量 localStorage.getItem("key");//获取存储的变量key的值www.it165.net localStorage.key;//获取存储的变量key的值 localStorage.removeItem("key")//删除变量名为key的存储变量

//以上即为localStorage调用的方法。下面介绍存储JSON对象的方法。var students = {liyang:{name:"liyang",age:17},lilei:{name:"lilei",age:18}}//要存储的JSON对象students = JSON.stringify(students);//将JSON对象转化成字符串localStorage.setItem("students",students);//用localStorage保存转化好的的字符串

//上面即可保存JSON对象，接下来我们在要使用的时候再将存储好的students变量取回 var students = localStorage.getItem("students");//取回students变量 students = JSON.parse(students);//把字符串转换成JSON对象 //以上即可得到存储的students的JSON对象了

utils = {    setParam : function (name,value){        localStorage.setItem(name,value)    },    getParam : function(name){        return localStorage.getItem(name)    }}product={    id:0,    name:"",    num:0,    price:0.00};orderdetail={    username:"",    phone:"",    address:"",    zipcode:"",    totalNumber:0,    totalAmount:0.00    }cart = {    //向购物车中添加商品    addproduct: function (product) {        var ShoppingCart = utils.getParam("ShoppingCart");        if (ShoppingCart == null || ShoppingCart == "") {            //第一次加入商品            var jsonstr = { "productlist": [{ "id": product.id, "name": product.name, "num": product.num, "price": product.price}], "totalNumber": product.num, "totalAmount": (product.price * product.num) };            utils.setParam("ShoppingCart", "'" + JSON.stringify(jsonstr));        } else {            var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));            var productlist = jsonstr.productlist;            var result = false;            //查找购物车中是否有该商品            for (var i in productlist) {                if (productlist[i].id == product.id) {                    productlist[i].num = parseInt(productlist[i].num) + parseInt(product.num);                    result = true;                }            }            if (!result) {                //没有该商品就直接加进去                productlist.push({ "id": product.id, "name": product.name, "num": product.num, "price": product.price });            }            //重新计算总价            jsonstr.totalNumber = parseInt(jsonstr.totalNumber) + parseInt(product.num);            jsonstr.totalAmount = parseFloat(jsonstr.totalAmount) + (parseInt(product.num) * parseFloat(product.price));            orderdetail.totalNumber = jsonstr.totalNumber;            orderdetail.totalAmount = jsonstr.totalAmount;            //保存购物车            utils.setParam("ShoppingCart", "'" + JSON.stringify(jsonstr));        }    },    //修改给买商品数量    updateproductnum: function (id, num) {        var ShoppingCart = utils.getParam("ShoppingCart");        var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));        var productlist = jsonstr.productlist;        for (var i in productlist) {            if (productlist[i].id == id) {                jsonstr.totalNumber = parseInt(jsonstr.totalNumber) + (parseInt(num) - parseInt(productlist[i].num));                jsonstr.totalAmount = parseFloat(jsonstr.totalAmount) + ((parseInt(num) * parseFloat(productlist[i].price)) - parseInt(productlist[i].num) * parseFloat(productlist[i].price));                productlist[i].num = parseInt(num);                orderdetail.totalNumber = jsonstr.totalNumber;                orderdetail.totalAmount = jsonstr.totalAmount;                utils.setParam("ShoppingCart", "'" + JSON.stringify(jsonstr));                return;            }        }    },    //获取购物车中的所有商品    getproductlist: function () {        var ShoppingCart = utils.getParam("ShoppingCart");        var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));        var productlist = jsonstr.productlist;        orderdetail.totalNumber = jsonstr.totalNumber;        orderdetail.totalAmount = jsonstr.totalAmount;        return productlist;    },    //判断购物车中是否存在商品    existproduct: function (id) {        var result = false;        var ShoppingCart = utils.getParam("ShoppingCart");        if (ShoppingCart != null) {            var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));            var productlist = jsonstr.productlist;            for (var i in productlist) {                if (productlist[i].id == id) {                    result = true;                }            }        }        return result;    },    //删除购物车中商品    deleteproduct: function (id) {        var ShoppingCart = utils.getParam("ShoppingCart");        var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));        var productlist = jsonstr.productlist;        var list = [];        for (var i in productlist) {            if (productlist[i].id == id) {                jsonstr.totalNumber = parseInt(jsonstr.totalNumber) - parseInt(productlist[i].num);                jsonstr.totalAmount = parseFloat(jsonstr.totalAmount) - parseInt(productlist[i].num) * parseFloat(productlist[i].price);            } else {                list.push(productlist[i]);            }        }        jsonstr.productlist = list;        orderdetail.totalNumber = jsonstr.totalNumber;        orderdetail.totalAmount = jsonstr.totalAmount;        utils.setParam("ShoppingCart", "'" + JSON.stringify(jsonstr));    }};

//上面的基于html5 localStorage的购物车JS脚本使用方法var product ={'id': id,        //属性名用引号括起来，属性间由逗号隔开'name': 'hhh','num':jq('#text-4').val(),'price':199.9};//商品加入到购物车cart.addproduct(product);var productlist=cart.getproductlist();//取出购物车商品alert('', '商品:'+productlist[0].id+' '+productlist[0].name+' '+productlist[0].num+' '+productlist[0].price, '确定');