Problem solving of global variable caching in WeChat applet development

let Btel = '',//防止用户恶意修改手机号
    Byzm = '';

handleTel(e) {// 这里修改用户输入的手机号
        this.setData({
            tel:e.detail.value 
        })
    },
    handleYzm(e) {
        this.setData({
            Yzm:e.detail.value
        })
        Byzm = e.detail.value;        let psd = this.data.psd,
            yzm = this.data.Yzm;
        yzm == psd ? this.setData({isYzm:0}):'';
    },    handleGetYzm() {        let reg = common.telReg,
            val = this.data.tel;    
        if (!reg.test(val)) {
               wx.showModal({
                content:'请输入正确的手机号',
                showCancel:false,
                confirmColor:'#3cc51f',//默认值为#3cc51f
                success:res =>{                    if(res.confirm){
                        this.setData({
                            tel:''
                        })         
                    }
                }
            })
        }else {//发送验证码的时候用全局变量的手机号
            Btel = val;// 这里是全局的手机号    
            this.setData({
                isReset : true,
                isNoClick: true
            })
            const data ={
                tel:val//传的是全局变量 
            };
            utils.sendRequest(api.YanZhengMa, data, this.handleGetYzmSucc.bind(this));
            //button 定时器            let time = setInterval(()=>{            let phoneCode = this.data.time;
                phoneCode --
                this.setData({
                    time : phoneCode
                })                if(phoneCode == 0){
                     clearInterval(time)
                     this.setData({
                        isReset : false,
                        isNoClick: false,
                        time:60
                     })
                }
            },1000)
        }
        
            
    },

//然后这一步是校验了用户在请求完验证码接口后 有没有修改手机好 然后保存handleSave() {        let name = this.data.name,
            telNum = this.data.tel,
            yzm = Byzm,
            status = this.data.isYzm,
            card = wx.getStorageSync('UserCard');        let timestamp= new Date().getTime();        if (yzm == '') {
            wx.showModal({
                content:'请输入验证码.',
                showCancel:false,
                confirmColor:'#3cc51f'
            })            return false;
        }        if (name!=''&&telNum!='') {            if(Btel != telNum) {
                utils.showModal('手机号发生变化，请重新获取验证码。');
            }else {
                const data ={
                distribution_id:card.distribution_id,
                post:{
                    user_name:name,
                    user_tel:Btel,
                    user_code:yzm
                },
                user_id:card.user_id,
                password:yzm+timestamp
                };
                utils.sendRequest(api.BindTel, data, this.handleSaveTel.bind(this));
            }
        }else {
            utils.showModal('请填写完整信息哟');
        }
    },

// 然后在 保存成功之后 用户点击确定  清空 全局变量  也可以在隐藏和卸载的生命周期里面清空全局变量。
handleSaveTel(res) {        if (res.data.error == 0) {            let go = this.data.go,
                id = res.data.data.id,
                lv = res.data.data.level;
            wx.showModal({
                content:'绑定成功~',
                showCancel:false,
                confirmColor:'#3cc51f',//默认值为#3cc51f
                success:res =>{                    if(res.confirm){
                        Byzm = '';//对小程序全局变量缓存进行清除                        if (go) {
                            wx.redirectTo({
                              url: '/pages/user/cash/cash'
                            })
                        }else {                            if (id != 0) {                                let card = wx.getStorageSync('UserCard');
                                card.distribution_id = id;
                                card.distribution_level = lv;
                                wx.setStorageSync('UserCard',card);
                                wx.setStorageSync('seller', true)
                            }
                            wx.switchTab({
                              url: '/pages/user/index'
                            })
                        }         
                    }
                }
            }) 
            return false
        }else {
            utils.showModal(res.data.err_msg);
        }
    }