How to get record id in lightning:recordEditForm?

Component:

1. <aura:component >  
2.       
3.     <div class="slds-box slds-theme_default">  
4.           
5.         <lightning:recordEditForm  objectApiName = "Opportunity"  
6.                                onsuccess = "{! c.handleSuccess }">  
7.             <lightning:inputField fieldName="Name" />  
8.             <lightning:inputField fieldName="StageName" />  
9.             <lightning:inputField fieldName="CloseDate" />  
10.             <lightning:inputField fieldName="AccountId" />  
11.           
12.             <lightning:button class="slds-m-top_small"   
13.                               variant="brand"   
14.                               type="submit"   
15.                               name="update" label="Update" />  
16.               
17.         </lightning:recordEditForm>  
18.               
19.     </div>  
20.       
21. </aura:component>  

Component Controller:

1. ({  
2.       
3.     handleSuccess : function(component, event, helper) {  
4.           
5.         var params = event.getParams();  
6.         alert(params.response.id);  
7.           
8.     }  
9.       
10. })  

Output: