How to select a row(s) of record from DataTable without using wrapper class in lightning

cmp

<aura:component implements="force:appHostable,flexipage:availableForAllPageTypes,flexipage:availableForRecordHome,force:hasRecordId,forceCommunity:availableForAllPageTypes,force:lightningQuickAction" access="global" controller="WrapperInLtngCC" >

<aura:attribute name="data" type="contact[]"/>

<aura:attribute name="columns" type="List"/>

<aura:attribute name="selectedRows" type="List"/>

<!--<aura:handler name="init" value="{! this }" action="{! c.init }"/>-->

<div class="space">

<lightning:button label="Show Contacts" title="Show Contacts" onclick="{! c.handleClick }"/>

<lightning:button label="Show selected contacts" title="Show selected contacts" onclick="{! c.showSelectedContacts }"/>

</div>

<lightning:datatable data="{! v.data }"

columns="{! v.columns }"

keyField="Id"

onrowselection="{!c.handleSelect}">

<!--hideCheckboxColumn="true"-->

</lightning:datatable>

</aura:component>

Controller(JS)

({

handleClick: function (cmp, event, helper) {

cmp.set('v.columns', [

                 { label: 'Contact Name', fieldName: 'Name', type: 'text'},

                 { label: 'Phone', fieldName: 'Phone', type: 'phone'},

                 { label: 'Email', fieldName: 'Email', type: 'email'}

             ]);

var action = cmp.get('c.getContacts');

action.setCallback(this, $A.getCallback(function (response) {

var state = response.getState();

if (state === "SUCCESS") {

cmp.set('v.data', response.getReturnValue());

                 } else if (state === "ERROR") {

var errors = response.getError();

console.error(errors);

                 }

             }));

$A.enqueueAction(action);

         },

showSelectedContacts: function (cmp, event, helper) {

var listCont = cmp.get("v.selectedRows");

for(var i=0;i<listCont.length;i++){

alert(listCont[i].Name);    

            }           

         },

handleSelect: function(cmp, event, helper){

var selectedRows = event.getParam('selectedRows');

//alert(selectedRows);

//var setRows = [];

cmp.set("v.selectedRows",selectedRows);

         }

})

ApexController

public with sharing class WrapperInLtngCC {

/*  

    @AuraEnabled public Contact cont {get;set;}

    @AuraEnabled public boolean isSelected {get;set;}        

    public WrapperInLtngCC (Contact con, boolean b){

        cont = con;  

        isSelected = b;

    }*/

@AuraEnabled

public static List<Contact> getContacts() {

List<Contact> contacts =

                [SELECT Id, Name, Phone, Email FROM Contact];

//Add isAccessible() check

return contacts;

    }

}

CSS

.THIS.space {

padding-bottom: 2%;

}

On clicking on Show Contact button

Select some records & click on Show Selected Contact button