Salesforce

1) Consider this scenario I  have a profile  by name 'ProvideReadAccess' and two users U1 and U2 assigned to it. And I have object X. My Question is I want to have ReadWrite access for U1 and ReadOnly access for U2  for the object X. How do I do this? Answer: Read Access for both users is common hence in the Profile settings give 'Read' access for the object 'X' By doing this User U2 will be able to read all the records( One condition satisfied) but U1 will also be able to only read the records(Second condition not satisfied). So next what do we do is we create a permission set say 'GrantWriteAccess' and in this permission set we give the object 'X' the Write access and assign the user U1 to this permission set.(2nd condition satisfied). Explanation about when and where to use permission set and profile https://success.salesforce.com/answers?id=90630000000grVPAAY 2) Consider a scenario I have not given any CRUD...

Difference between Sandbox and Developer Edition a) Using the Sandbx  we can copy the configurations and/or data from live instance/Production instance directly to Sandbox. But In Developer edition we cannot copy anything  from production/salesforce.com instance. Every thing should be manually done by the user. b) If we purchase Unlimited Edition, then Sandboax is included in the cost  but If we purchase Enterprise,professional or Group editions then we have to seprately pay for Sandbox. But Developer edition is free of cost. Any one can start using developer edition free of cost c) Reason why do we have Sandbox and Developer edition? Sandbox is created so that we can have a instance which is exactly like production on which we can test and implement our changes and then move it production. But Developer Edition is more like development of integration and apps, specifically for the AppExchange and a great place to learn/test/train users in salesforce....

When do we use '!' symbol  in visualforce page. Let understand this clearly with a small example. Consider the 'Rendered' property in Visualforce page. This property is used when we have  to display/hide a field on the visualforce page. And how we do that? Like this: <apex:form Rendered="True"> The above line means that the specific form should be displayed when the value is True. This is more like hardcoding and this remains same unless we change it to "false". Now lets say we have a criteria where user decides if the form should be displayed or not which would mean we cannot gauge what user would choose at the run time. Hence we would need some mechanism where we can get the value dynamically, How do we do that? Like this: <apex:form Rendered="{!checkStatusValue}"> So Which means that when we have to fetch a Variables value in the run time/dynamically we use '!' in front of the variable in visualforce