Ajax

先写几个按钮

<button onclick="fn('user','光头强',1)">增加值</button>
<button onclick="fn('user','天线宝宝',1)">修改值</button>
<button onclick="fn('user')">删除值</button>
<button onclick="fn2('user')">获取值</button>

<script>
增加删除修改
    function fn(name, value, time) {
        let oDate = new Date();
        if (value != undefined) {
            oDate.setDate(oDate.getDate() + time)
            document.cookie = name + '=' + value + ';expires=' + oDate;
        } else {
            oDate.setDate(oDate.getDate() - 1)
            document.cookie = name + '=;expires=' + oDate;
        }

    }

获取

    function fn2(name) {
        let str = document.cookie
        let arr1 = str.split(';')
        console.log('arr1', arr1);
        for (var i = 0; i < arr1.length; i++) {
            // console.log('arr1[i]', arr1[i]);
            var arr2 = arr1[i].split('=');
            // console.log('第二个二数组', arr2);
            if (name == arr2[0].trim()) {
                console.log(arr2[1]);
            }
        }
    }

</script>