<apex:page controller="WrapperClassExample" sidebar="false">
    <apex:form > 
        <apex:pageBlock title="Wrapperclass example" id="refer">
            
            <apex:outputPanel id="pgrefresh">
                <apex:pageBlockTable value="{!allRecords}" var="allrcs" id="Refresh">
                    <apex:column headerValue="S.No" value="{!allrcs.RowNo}"/>
                    <apex:column headerValue="select">
                        <apex:inputCheckbox value="{!allrcs.chk}"/>
                    </apex:column>
                    <apex:column headerValue="Account">
                        <apex:inputText value="{!allrcs.acc.name}"/>
                    </apex:column>
                    <apex:column headerValue="Contact lastname" >
                        <apex:inputText value="{!allrcs.con.lastname}"/>
                    </apex:column>
                    <apex:column headerValue="Contact firstname" >
                        <apex:inputText value="{!allrcs.con.firstname}"/>
                    </apex:column>
                </apex:pageBlockTable>
            </apex:outputPanel>
            <apex:commandButton value="Update Records" action="{!updateRecords}" rerender="pgrefresh"/>
        </apex:pageBlock>        
    </apex:form>
</apex:page>



==================
public class WrapperClassExample {
    public list<innerwrapper> allRecords{get;set;}
    public integer RowNo{set;get;}
    public WrapperClassExample(){
        //RowNo = 1;
        allRecords = new list<innerwrapper>();
        list<contact> lstContacts = [select id,firstname,lastname,account.name from contact where account.name != null limit 10];
        for(integer i=0;i<lstContacts.size();i++){
            RowNo = i+1;
            innerwrapper iw = new innerwrapper(lstContacts[i].account,lstContacts[i],false,RowNo);
            allRecords.add(iw);
        }
        
    }
    public PageReference updateRecords(){ 
        boolean updflag = false;
         PageReference curPage;
        if(allRecords.size()>0){
            for(integer i=0;i<allRecords.size();i++){
                if(allRecords[i].chk == True){
                    system.debug('==allRecords[i]=='+allRecords[i]);
                    update allRecords[i].acc;
                    system.debug('==allRecords[i].acc=='+allRecords[i].acc);
                    update allRecords[i].con;
                     system.debug('==allRecords[i].con=='+allRecords[i].con);
                    updflag = true;
                }
            } 
        }
        if(updflag == true){
            curPage = page.WrapperClasExample; //new PageReference('/apex/Wrapperclasexample');
            curPage.setRedirect(true);            
        }
        return curPage;  
        
    }
    
    public class innerwrapper{
        public account acc{get;set;}
        public contact con{get;set;}
        public boolean chk{get;set;}
        public integer rowNo{get;set;}
        
        public innerwrapper(account a,contact c,boolean b,integer row){
            acc = a;
            con = c;
            chk = b;
            rowNo = row;
        }
        
    }
    
}