[Eswar Kumar]

Try this , It will be easy for you all to complete the challange.

Step1:

In the "campingListItem.cmp" paste this code  (ignore '' :P)

<aura:component >
    <aura:attribute name=”item” type=”Camping_Item__c” required=”true”/>
    <p>Name:
        <ui:outputText value = “{!v.item.Name}”/>
    </p>
    <p>Price:
        <lightning:formattedNumber value=”{!v.item.Price__c}” style=”currency”/>
    </p>
    <p>Quantity:
        <lightning:formattedNumber value=”{!v.item.Quantity__c}” style=”number”/>
    </p>
    <p>Packed:
        <lightning:input type=”toggle” label=”Packed?” checked=”{!v.item.Packed__c}”/>
    </p>
    <div>
        <lightning:button label=”Packed!” onClick=”{!c.packItem}”/>
    </div>
</aura:component>

Step2:

create a controller to write the javascript code. ie campingListItemController.js and campingListController.js

Step3:

In campingListController.js, paste this code

({
    packItem : function(component, event, helper) {
        var btn = event.getSource();
        btn.set("v.disabled",true);
        component.set("v.item.Packed__c", "true");
    }
})

Step4: In "campingListItemController.js" Paste This Code

({
    packItem : function(component, event, helper)
    {
        var checkbox = component.get("v.item",true);
        checkbox.Packed__c= true;
        component.set("v.item",checkbox);
        event.getSource().set('v.disabled',true);
    }
})

Now you can save them and check Challange. It will pass 100%.

Thanks you,
Eshu