Dependent Picklist Creation in VisualForce

In this scenario we can see how to generate a picklist dynamically and preparation of dependant picklists.
Here dependant picklist  will be populated using apex:actionsupport.

Example: VisualForce Page To display Contacts based on the accounts selection.

Page:

<apex:page sidebar="false" controller="DependentClassabcd">

<apex:form >

Accounts : <apex:selectList value="{!SelectedAccount}" multiselect="false" size="1">

                <apex:actionSupport event="onchange" reRender="out"/>

                <apex:selectOptions value="{!Accounts}">

                </apex:selectOptions>

            </apex:selectList> <br/>

Contacts : <apex:selectList multiselect="false" id="out" size="1">

                <apex:selectOptions value="{!Contacts}">

                </apex:selectOptions>

            </apex:selectList>

</apex:form>   

</apex:page>

Controller:

public with sharing class DependentClassabcd {

public string selectedaccount {get;set;}

List<selectOption> Cons = new List<selectOption>();

List<selectOption> Accs = new List<selectOption>();

    public List<selectOption> getContacts() {

        Cons.clear();

        Cons.add(new selectOption('–None–','–None–'));

        for(contact objEmp : [select Id,name,accountid from contact where accountid=:selectedaccount and accountid!=null order by name asc ]){

            Cons .add(new selectOption(objEmp.name,objEmp.name));

        }

        return Cons;

    }

    public List<selectOption> getAccounts() {

        Accs.add(new selectOption('–None–','–None–'));

        for(account objDept : [select id,name from account order by Name Asc]){

            Accs.add(new selectOption(objDept.id,objDept.name));

        }

        return Accs;

    }

}