console 命令行工具 X clear

console

function localStorageFuc() {
    if (!window.localStorage) {
        alert("浏览器不支持localstorage");
        return false;
    } else {
        // =============================== 存localStorage
        var storage = window.localStorage;
        // 方法1
        storage["a"] = 1;
        // 方法2
        storage.b = 1;
        // 方法3  推荐
        storage.setItem("c", 3);
        // string  int类型打印出来是string
        // localstorage只支持string类型的存储
        // =============================== 取localStorage
        var storage = window.localStorage;
        // 方法1
        var a = storage.a;
        // 方法2
        var b = storage["b"]
        // 方法3 推荐
        var c = storage.getItem("c");
        for(let i=0;i<storage.length;i++){
            var key =storage.key(i);
        }
        // =============================== 修改localStorage
        var storage = window.localStorage;
        storage.b = 4; // 直接修改
        // =============================== 删除localStorage
        // 移除所有
        localStorage.clear();
        // 删除某个键值对
        localStorage.removeItem("a");
    }
}
function myCookie() {
    //添加cookie
    function setCookie(key, value, iDay) {
        var oDate = new Date();
        oDate.setDate(oDate.getDate() + iDay);
        document.cookie = key + '=' + value + ';expires=' + oDate;

    }
    //删除cookie
    function removeCookie(key) {
        setCookie(key, '', -1);//这里只需要把Cookie保质期退回一天便可以删除
    }
    //获取cookie
    function getCookie(key) {
        var cookieArr = document.cookie.split('; ');
        for(var i = 0; i < cookieArr.length; i++) {
            var arr = cookieArr[i].split('=');
            if(arr[0] === key) {
                return arr[1];
            }
        }
        return false;
    }
}
// ========================================= localStorage
sessionStorage.setItem("clickcount", "0");
var btn = document.getElementById("btnSession");
btn.addEventListener("click",function () {
    sessionStorageFuc();
});
function sessionStorageFuc() {
    if (sessionStorage.clickcount) {
        sessionStorage.clickcount = Number(sessionStorage.clickcount) + 1;
    } else {
        sessionStorage.clickcount = 1;
    }
    document.getElementById("content").innerHTML = "你在按钮上已经点击了 " +
        sessionStorage.clickcount + " 次。";
};

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>测试页面</title>
</head>
<body>
    <div>
        测试cookie, localStorage和sessionStorage<br/>
        具体代码看JS部分, localStorage和sessionStorage代码基本是一样的
    </div>
    <div id="btnSession">sessionStorage</div>
    <div id="content"></div>
</body>
</html>

#btnSession{
    margin: 8px;
    /* height: 30px; */
    text-align: center;
    color: white;
    background: #e09c9c;
    box-shadow: 0 0 4px 4px #fddada;
    -webkit-border-radius: 4px;
    -moz-border-radius: 4px;
    border-radius: 4px;
    cursor: pointer;
}