Wrappper class ex

1. Create  a wrapper class with elements
1. name :String
2. code :String
3. price :Decimal
Solution :
----------
public class ProdWrapper {
    public String name {set;get;}
    public String code {set;get;}
    public Decimal price{set;get;}
}

2. Create a class ProductList with following members
     1.products :List<ProdWrapper>  // This will contain the intial list of product that we want to display
     2.myList   : List<ProdWrapper> // This will contain the list
prodWrapper elements whose
name is not null

    3. ProductList() : Assign the memory for Products and
add two prodWrapper  elements to the list

    4. addMore(): void : When ever this method is called add two
prodWrapper elements to the list

Snippet :
public void addMore(){
        for(Integer i=1;i<=2;i++){
            ProdWrapper pw=new ProdWrapper();
            products.add(pw);
        }
    }

   5: clearAll() :void : When this method is called remove all the
elements from the products list

Snippet:
public void clearAll(){
           products.clear();
         }

   6: submit() : When call this methods all the ProdWrapper                 elements from product list whose name is not null                 put those prodWrpper elements into mylist
 
Snippet :
public void submit(){
        myList=new List<ProdWrapper>();
        for(ProdWrapper p:Products){
            if(p.name!=null && p.name!=''){
                mylist.add(p);
            }
        }
    }

Complete Class :
==================

public class ProductList {
    public List<ProdWrapper> products {Set;get;}
    public List<ProdWrapper> myList  {Set;get;}
    public ProductList(){
        products=new List<ProdWrapper>();
        addMore();
    }
    public void addMore(){
        for(Integer i=1;i<=2;i++){
            ProdWrapper pw=new ProdWrapper();
            products.add(pw);
        }
    }
    public void clearAll(){
        products.clear();
    }
    public void submit(){
        myList=new List<ProdWrapper>();
        for(ProdWrapper p:Products){
            if(p.name!=null && p.name!=''){
                mylist.add(p);
            }
        }
    }
}

VF Page :
---------
<apex:page controller="ProductList" >
    <apex:form>
    <apex:pageBlock title="Products">
        <apex:pageBlockButtons>
                <apex:commandBUtton value="Clear" action="{!clearAll}" />
                <apex:commandButton value="AddMore" action="{!addMore}" />
                <apex:commandButton value="Submit" action="{!submit}"  />
            </apex:pageBlockButtons>
            <apex:pageBlockTable value="{!products}" var="a">
                <apex:column >
                    <apex:inputText value="{!a.name}" />
                </apex:column>
                 <apex:column >
                    <apex:inputText value="{!a.price}" />
                </apex:column>
                 <apex:column >
                    <apex:inputText value="{!a.code}" />
                </apex:column>
            </apex:pageBlockTable>
        </apex:pageBlock>
  <apex:pageBlock title="Products" rendered="{! !ISNULL(mylist)}">
            <apex:pageBlockTable value="{!mylist}" var="a">
                <apex:column value="{!a.name}" />
                <apex:column value="{!a.price}"   />
                <apex:column value="{!a.code}" />
            </apex:pageBlockTable>
        </apex:pageBlock>
    </apex:form>
</apex:page>

===============================================================
Example 2:
===============================================================
1. Create a class with following members
1.options :List<SelectOption> : This will contain the list
  of options created

2.selected : String : This will contain the value based
on the option selected

3.result :


public class PickExample {
    public List<SelectOption> options {set;get;}
    public String selected {Set;get;}
    public String result {set;get;}
    public PickExample(){
        options=new List<SelectOption>();
        SelectOption op1=new SelectOption('none','-None-');
        SelectOption op2=new SelectOption('TG','Hyd');
        SelectOption op3=new SelectOption('TN','Che');
        SelectOption op4=new SelectOption('KA','Ban');
        options.add(op1);
        options.add(op2);
        options.add(op3);
        options.add(op4);
    }
    public void callme(){
        result='You Have selected :'+selected;
    }
}


VF Page:
========
<apex:page  controller="PickExample">
    <apex:form>
    <apex:pageBlock title="PickList">
            <apex:outputLabel value="Cities" />
            <apex:selectList size="1" value="{!selected}" >
                <apex:selectOptions value="{!options}" />
                <apex:actionSupport event="onchange" action="{!callme}" reRender="res" />
            </apex:selectList>
            <apex:outputLabel value="{!result}" id="res" />
        </apex:pageBlock>
    </apex:form>
</apex:page>
================================================================

Example 3:
1. Create a wrapper class ProdWrapper with following
1. prodName;
2. prodCode;

 public class ProdWrapper{
public String prodName;
public String prodCode;

 }


2. Create a List<ProdWrapper>  and three prodWrapper objects to
   it

List<ProdWrapper> products=new List<ProdWrapper>();

ProdWrapper pw1=new ProdWrapper();
pw1.prodName='Dell';
pw1.prodCode='D-01';

ProdWrapper pw2=new ProdWrapper();
pw2.prodName='TCS';
psw.prodCode='T-01';

products.add(pw1);
products.add(pw2);

3. Create  a list<SelectOption> and create SelectOption with

prodName as label and prodcode value from the product list

List<SelectOption> options=new List<SelectOption>();

 for(ProdWrapper p: products){

SelectOption sp=new SelectOption(p.prodCode,p.prodName);
options.add(sp);

 }