checkbox為什么要操作后臺傳來的true和false值？

要實(shí)現(xiàn)選取不同的checkbox值，給后臺傳值，但是，為什么要操作后臺傳來的true和false呢？

<div ng-repeat='item in ctrl.nndata'>
                <input type="checkbox" ng-click='ctrl.chck(item)'>
</div>

后臺假數(shù)據(jù)

this.nndata=[{
            paratetime: 'page',
            name: '12345',
            displayname: '組織管理',
            isdranted: false,
        },{
            paratetime: 'page',
            name: '12345',
            displayname: '組織管理',
            isdranted: false,
        }]
    }

  chck(data){
        let kong=this.kong=[];
        let datasss=this.nndata;
        if(data.isdranted){
            kong.map(function(ite,index){
                if(ite==data.name){
                    kong.splice(index,1)
                    datasss.map(function(dd,ix){
                        if(dd.name==data.name){
                            console.log(dd.name)
                            datasss[ix]['isdranted']=false
                            console.log(datasss[ix]['isdranted'])
                        }
                    })
                }
            })
        }else{
            kong.push(data.name)
            datasss.map(function(dd,ix){
                 if(dd.name==data.name){
                    console.log(dd.name)
                            datasss[ix]['isdranted']=true
                            console.log(datasss[ix]['isdranted'])
            }
            })
            this.nndata=datasss
            console.log(datasss)
        }
        console.log(kong)
        this.kong=kong;
    }