Question

我正在尝试使用javascript模拟会话。大多数情况下，将用户凭据保存到LocalStorage中，然后与数组进行比较。我在var oStoredCredentials = JSON.parse(localStorage.savedCredentials);行上收到意外的输入结果，我找不到答案。这是整个代码块：

$(document).on("click", ".submitBtnLog", function(){
        var sUsername = $("#LoginName").val();
        var sPassword = $("#LoginPassword").val();

     for(var i=0; i< aEmployees.length; i++){
        if(sUsername == aEmployees[i].username && sPassword == aEmployees[i].password){
            login = true;                
            var sUsername = aEmployees[i].username;
            var sPassword = aEmployees[i].password;
            var oCredentials = {"savedUsername":sUsername,"savedPassword":sPassword};
            var sCredentials = JSON.stringify(oCredentials);
            localStorage.savedCredentials = sCredentials;

        }
    }
});
/*CHECK IF USER HAS ALREADY STARTED A "SESSION"*******************************************************************************/

if (localStorage.getItem("savedCredentials") === null) {
    localStorage.savedCredentials = [];
}else{
    var oStoredCredentials = JSON.parse(localStorage.savedCredentials);
    //console.dir(oStoredCredentials.savedUsername)
    for(var i=0; i< aEmployees.length; i++){
        if(oStoredCredentials.savedUsername==aEmployees[i].username && oStoredCredentials.savedPassword==aEmployees[i].password){
            login = true;
        }

    if(login === true){
                    var BoxHtml="Welcome "+aEmployees[i].name +" "+aEmployees[i].surname; 
                    $("#Navigation").css({"display":"block"});
                    $("#LoginContainer").html(BoxHtml);
    }else{
        console.log(error);
            };
     };
};

Answer 1

我设法重现了你的问题。由于localStorage.savedCredentials行，它接缝localStorage.savedCredentials = [];存储空数组而不存储字符串化对象。

您应该仔细检查您的代码并确保localStorage.savedCredentials始终是您所期望的。

Answer 2

当localStorage为null时，您正在存储[]。因此，当else部分开始执行时，需要[]作为要解析的值，并且它在此中发现困难。当localStorage为null时，更改存储[]的逻辑。

Answer 3

我创建了一些如何使用localStorage的简单代码。

这是我的 HTML 代码：

<input id="LoginName" />
<input id="LoginPassword" />
<input id="submitBtnLog" type='button' value="Submit" />
<input id='btnGetLocalStorage' type='button' value='Get Local Storage' />

这是我的 Javascript 代码：

var Credentials = {
    sUsername: '',
    sPassword: ''
}

$('#submitBtnLog').click(function(){
    Credentials.sUsername = $("#LoginName").val();
    Credentials.sPassword = $("#LoginPassword").val();
    localStorage.setItem('savedCredentials', JSON.stringify(Credentials));

});

$('#btnGetLocalStorage').click(function(){
    if(localStorage.getItem('savedCredentials') != null){   
        var oStoredCredentials = JSON.parse(localStorage.getItem('savedCredentials'));    
        alert('Username = ' + oStoredCredentials.sUsername + '    Password = ' + oStoredCredentials.sPassword);
        localStorage.removeItem('savedCredentials')
    }
});

如果您需要有关如何使用localstorage的其他信息，请与我们联系。

意外的输入结束（javascript和JSON）

3 个答案: