how to display map on vf page in salesforce

Question

how to create a map that contains the account and list of corresponding contacts then we have to display this map on a VF page.

Answer 1

So you can create a map. this map can contain Account and there related contact records.

Like

map<Account, List<Contact>> mapAccountToContacts = new map<Account, List<Contact>>();

SO basically if you are using this map in your vf page then this variable should be in get set property

public class myClaass{
public map<Account, List<Contact>> mapAccountToContacts {get;set;}

  public myClaass(){
    mapAccountToContacts = map<Account, List<Contact>>();
    // query here and add into this map
  }
} 

If you just wanted to display these records then use private set This is reduce view state and you can't update records from page.

And add the values in map. You can use subquery to get the contacts related to each Account record.

And then you can assign to map.

for(Account objAcc :[SELECT Name, (SELECT FirstName, LastName FROM Contacts) FROM Account])
{
    mapAccountToContacts.put(objAcc, objAcc.Contacts);
}

In VF page. You need 2 apex:repeat. One apex:repeat to iterate over map and another apex:repeat to iterate over list contacts that are associated with each Account record.

<apex:repeat value="{!mapAccountToContacts}" var="mapAccKey">
    Account Name: {!mapAccKey.Name}

    <apex:repeat value="{!mapAccountToContacts[mapAccKey]}" var="con">
    Contacts First Name :{!con.LastName}
    Contacts Last Name  :{!con.LastName} 
    </apex:repeat>
</apex:repeat>