js

 1.mobile.substr(0,3) + "****"+mobile.substr(8)

 2.mobile.replace(new RegExp("(\\d{3})(\\d{4})(\\d{4})"),"$1****$3")

vue

使用Filter

export default {
   filters:{
       mobile(value){
        let start = value.slice(0, 3)
        let end = value.slice(-4)
        return '${start}****${end}'
     }
  }
}

使用  {{ phoneNo|mobile}}