WeChat applet implements a simple calculator

// pages/jisuanqi/jisuanqi.js
Page({

  /**
   * Initial data of the page */
  data: {
    result:"0",
    string:"",
    cal:"",
    num1:"",
    num2:""
  },
  btSubmit:function(e){
    console.log(e);
    var num1 = this.data.num1;
    var cal = this.data.cal;
    var num2 = this.data.num2;
    var char= e.target.id;
    var string ;
    if((char>="0"&&char<="9"||char=='.')&&cal==""){
      num1=num1+char;
      this.setData({
        num1:num1,
      })
    }
    else if((char>="0"&&char<="9"||char=='.')&&cal!=""){
      num2=num2+char;
      this.setData({
        num2:num2,
      })
    }
    else {
      cal=char;
      this.setData({
        cal:cal,
      })
    }
    this.setData({
     string:num1+cal+num2
    })
  },
  clean:function(e){
    this.setData({
      string:"",
      num1:"",
      num2:"",
      cal:""
    })
  },
  calculate:function(e){
    var num1 = this.data.num1;
    var num2 = this.data.num2;
    var cal = this.data.cal;
    var result;
    switch(cal){
      case '+':result=num1*1+num2*1;break;
      case '-':result=num1*1-num2*1;break;
      case '*':result=(num1*1)*(num2*1);break;
      case '/':result=(num1*1)/(num2*1);break;
    }
    num1=result;
    cal="";
    num2="";
    this.setData({
      result:result,
      num1:num1,
      cal:cal,
      num2:num2
    })
  },
  reverse:function(e){
    var cal = this.data.cal;
    var num1 = this.data.num1;
    var num2 = this.data.num2;
    if(cal==""){num1="-";}
    else if(cal!=""){num2="-"}
    this.setData({
      num1:num1,
      num2:num2
    })
  },
  lololo:function(e){
    console.log(123)
  },
  confirm:function(e){
    console.log(555);
    console.log(e)
  },
  event:function(e){
    wx.navigateTo({
      url: '/pages/event/event',
    })
  },
  bindinput:function(e){
    console.log(1)
  },
  jisuanqi:function(e){
    var n1=e.detail.value.num1;
    var n2=e.detail.value.num2;
    var result=n1*1+n2*1;
    console.log(n1);
    console.log(n2);
    console.log(result);
    this.setData({
      result:result
    })
  },
  tiaozhuan:function(e){
    wx.navigateTo({
      url: '/pages/9x9form/9x9form',
    })
  },
  /**
   * Life cycle function--listen for page loading*/
  onLoad: function (options) {

  },

  /**
   * Life cycle function - listen for the completion of the initial rendering of the page*/
  onReady: function () {

  },

  /**
   * Life cycle function--monitor page display*/
  onShow: function () {

  },

  /**
   * Life cycle function--listen for page hiding*/
  onHide: function () {

  },

  /**
   * Life cycle function--monitor page uninstallation*/
  onUnload: function () {

  },

  /**
   * Page related event processing function - listen to user pull-down action */
  onPullDownRefresh: function () {

  },

  /**
   * The function that handles the bottoming event on the page*/
  onReachBottom: function () {

  },

  /**
   * User clicks on the upper right corner to share*/
  onShareAppMessage: function () {

  }
})

{
  "usingComponents": {},
  "navigationBarTitleText": "Calculator"
}

<view class="container">
  <view class="view1">{{string}}</view>
  <view class="view2">{{result}}</view>
  <view class="button-group">
    <button class="button">History</button>
    <button class="button" bindtap="clean">C</button>
    <button class="button"></button>
    <button class="button" id="/" bindtap="btSubmit">/</button>
  </view>
  <view class="button-group">
    <button class="button" id="7" bindtap="btSubmit">7</button>
    <button class="button" id="8" bindtap="btSubmit">8</button>
    <button class="button" id="9" bindtap="btSubmit">9</button>
    <button class="button" id="*" bindtap="btSubmit">*</button>
  </view>
  <view class="button-group">
    <button class="button" id="4" bindtap="btSubmit">4</button>
    <button class="button" id="5" bindtap="btSubmit">5</button>
    <button class="button" id="6" bindtap="btSubmit">6</button>
    <button class="button" id="-" bindtap="btSubmit">-</button>
  </view>
  <view class="button-group">
    <button class="button" id="1" bindtap="btSubmit">1</button>
    <button class="button" id="2" bindtap="btSubmit">2</button>
    <button class="button" id="3" bindtap="btSubmit">3</button>
    <button class="button" id="+" bindtap="btSubmit">+</button>
  </view>
  <view class="button-group">
    <button class="button" bindtap="reverse">-(minus sign)</button>
    <button class="button" id="0" bindtap="btSubmit">0</button>
    <button class="button" id="." bindtap="btSubmit">.</button>
    <button class="button" bindtap="calculate">=</button>
  </view>
</view>
<navigator url="/pages/event/event">Jump to event</navigator>//

.button{
  width: 160rpx;
  height: 100rpx;
  margin-left: 10rpx;
  padding-left: 10rpx;
  margin-top: 10rpx;
  text-align: center;
  line-height: 100rpx;
  padding: 5px;
  border-radius: 5px;
}
.button-group{
  display: flex;
  flex-direction: row;
  align-content: flex-start;
}
.container{
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  /* align-content: flex-end; */
}
.view1{
  height: 100rpx;
  background-color: #e4e4e4;
  line-height: 100rpx;
  font-size: 20px;
}
.view2{
  height: 100rpx;
  margin-top: 5px;
  background-color: #e4e4e4;
  line-height: 100rpx;
  font-size: 20px;
}