<view>第一个数：{
   
   {first}}</view>
<view>第二个数：{
   
   {second}}</view>
<view>和为：{
   
   {sum}}</view>

data() {
    
    
	return {
    
    
		first:10,
		second:20,
	}
},
computed: {
    
    
	sum(){
    
    
		return this.first + this.second;
	},
},