Question

function book()
{<br/>
  var name=document.getElementById('name').value;
  <br/>var date=document.getElementById('date').value;
  <br/>var venue=document.getElementById('venue').value;
  <br>var time=document.getElementById('time').value;

 <br/> var reserve=[];
 <br/> 
var input={
           >> name:' ',<br/>
            date:' ',<br/>
            venue:' ',<br/>
            time:' '<br/>
        };


        //load local storage
        reserve = localStorage.getItem("arrayCache");
        reserve = JSON.parse(reserve);
        if(reserve === null || reserve === undefined)//run for the first time
        {

                input={ name:name,
                        date:date,
                        venue:venue,
                        time:venue
                       };
                input=JSON.stringify(input);
                alert(input);

                reserve.push(input);
                localStorage.setItem("arrayCache",JSON.stringify(reserve));
                alert("Data successfully stored.");
         }
         //when array already store data
         else
         {
                for(var x=0; x<reserve.length;x++)
                    {
                            if(date==reserve[x].date && venue==reserve[x].venue && time==reserve[x].time)
                              {
                                    alert("Date and time not available for that venue!");
                                    break;
                              }
                            else
                              {

                                    input={ name:name,
                                            date:date,
                                            venue:venue,
                                            time:venue
                                           };
                                    input=JSON.stringify(input);
                                    alert(input);
                                    reserve.push(input);

                                    localStorage.setItem("arrayCache",JSON.stringify(reserve));
                                    alert("Data successfully stored.");
                                    break;
                              }
                    }
         }

}

我的问题是当我试图存储对象时

input={ name:name,
        date:date,
        venue:venue,
        time:venue
       };

到数组reserve[] 使用reserve.push(input) 它会提示错误，说明＆＃34;无法读取属性＆＃39;推送＆＃39; of null＆＃34;，但是当我尝试alert(input)时，它很好地打印出整个对象，我不知道问题出在哪里。我的预期输出将是这样的：

reserve(0)={name:name,
            date:date,
            venue:venue,
            time:time}

以便稍后我可以与reserve(0).name == name

进行比较并检查新用户输入

Answer 1

您只需要实例化array即可。

您的错误是抛出原因

reserve = localStorage.getItem("arrayCache");
reserve = JSON.parse(reserve);

不要返回array，您需要在push item之前进行测试。

它在实例化之后起作用

var name ="name";
var date ="10/10/2016";
var type="text";
var reserve;

var input = {
  name:name,
  date:date,
  type:type
};

//Test if array exist and if it's an array
reserve = ( typeof x != 'undefined' && reserve instanceof Array ) ? reserve : []

reserve.push(input);

console.log(reserve)

使用数组javascript中的属性存储对象

1 个答案: