How vue+checkbox operates data binding, acquisition and calculation

<input type=&#39;checkbox&#39; v-model=&#39;checkboxModel&#39; :value=&#39;z.coach_id+"-"+z.amount&#39; :i="dianji" @click="lll">

<span><input type=&#39;checkbox&#39; v-model=&#39;checked&#39; v-on:click=&#39;checkedAll&#39;><span class="select-all">全选</span></span>

return {
 dianji:'12',
 list: [],
 value:{},
 value1:{},
 checkAll: false,
 checkArr:[],
 checkboxModel:[],
 wodeshi:'0',
 checked:false
}
lll: function(){
 var self = this;
 var sum=0;
 setTimeout(function(){
 for(var x in self.checkboxModel){
 sum += parseInt(self.checkboxModel[x].split('-')[1])
 }
 self.wodeshi=sum;
 },0)
 // console.log(self.checkboxModel)
},
checkedAll: function() {
 var _this = this;
 if (this.checked) {//实现反选
 _this.checkboxModel = [];
 }else{//实现全选
 _this.checkboxModel = [];
 _this.list.forEach(function(z) {
 _this.checkboxModel.push(z.coach_id+'-'+z.amount);
 });
 }
 if(_this.checkboxModel.length==0){
 this.wodeshi=0;
 // console.log(_this.checkboxModel);
 }else {
 var self =this;
 var sum =0;
 for(var x in self.checkboxModel){
 sum += parseInt(self.checkboxModel[x].split('-')[1])
 }
 self.wodeshi=sum;
 }
},