如果/ Else声明为localStorage？

Question

我正在尝试使用localStorage创建一个If / Else语句但遇到问题。 我似乎无法将If语句链接到我的localStorage用户并始终获得Else语句。 如何迭代localStorage键并获取用户的值？

如果我能以某种方式定位ID 1，ID 2，ID 3等，那对我来说是有意义的但是如何？

IF / ELSE代码：

User.$button_login.addEventListener("click", function(entry) {

    for (var i = 0, len = localStorage.length; i < len; ++i) {
        console.log(localStorage.getItem(localStorage.key(i)));

    }

    if (document.getElementById("firstName").value == User.$form.user_name.value) {
        if (document.getElementById("passWord").value == User.$form.password.value) {
            alert("You have logged in");
        }
    } else {
        document.getElementById("negative").innerHTML = "Username or Password does not match"
    }


}, true);


},

用户代码：

var User = {
    index: window.localStorage.getItem("User:index"),
    $form: document.getElementById("userReg"),


    $button_register: document.getElementById("registerUser"),
    $button_login: document.getElementById("logIN"),

    init: function() {
        // initialize storage index
        if (!User.index) {
            window.localStorage.setItem("User:index", User.index = 1);
        }

        User.$form.addEventListener("submit", function(event) {
            var entry = {
                id: parseInt(this.id_entry.value),
                user_name: this.user_name.value,
                password: this.password.value
            };
            if (entry.id == 0) {
                User.storeAdd(entry);
            }
        }, true);

storeAdd: function(entry) {
        entry.id = User.index;
        window.localStorage.setItem("User:index", ++User.index);
        window.localStorage.setItem("User:" + entry.id, JSON.stringify(entry));
    },
};