Question

小提琴是here

我在以下结构localStorage.COMMENT_DESCRIPTION.list_no中添加了值，但它始终显示未定义。

但是当我打印到console.log时，它会显示数据。问题是当我检查条件时它无法正常工作

var comment_description = {};
$("#add_list_img").click(function()
{
    if(localStorage.COMMENT_DESCRIPTION)
    {
        alert(localStorage.COMMENT_DESCRIPTION.list_no);  # Here is the problem. I have added the value but the variable is empty
        if(localStorage.COMMENT_DESCRIPTION.list_no == undefined)
        {
            alert("Here so");
            cart_val =  localStorage.COMMENT_DESCRIPTION.list_no || 1;
            comment_description.list_no = cart_val+1;
            console.log(comment_description);
            storage();
        }
        else
        {   
            alert("here");          

            cart_val = comment_description.list_no;
            comment_description.list_no = cart_val+1;
            storage();
        }   
    }
    else
    {

        cart_val = 1;
        comment_description.list_no = cart_val+1;
        storage();
    }

});

function storage()
{
    if(localStorage.COMMENT_DESCRIPTION)
    {
        var oldItems = JSON.parse(localStorage.getItem('COMMENT_DESCRIPTION'));
        console.log("strogae "+comment_description.list_no);
        var newItems = $.extend({}, oldItems, comment_description);
        localStorage.setItem('COMMENT_DESCRIPTION',JSON.stringify(newItems));

    }
    else
    {   
        var lc_no = {"list_no":1,"card_no":1};
        var newItems = $.extend({},comment_description);
        localStorage.setItem('COMMENT_DESCRIPTION',JSON.stringify(newItems));
    }

        console.log("added following"+localStorage.COMMENT_DESCRIPTION);
}

Answer 1

您需要先解析它

JSON.parse(localStorage.COMMENT_DESCRIPTION).list_no

您的localStorage.COMMENT_DESCRIPTION的内容是JSON字符串，还不是对象

修改你的工作小提琴

https://jsfiddle.net/cyauyg0k/3/

从localStorage检查值但显示未定义

1 个答案: