ByVal vs ByRef Parameters in VB.net - Interview Question Answer

In VB.net, ByVal and ByRef are two different parameter passing mechanisms used when passing arguments to a function or subroutine. Here are the differences between ByVal and ByRef parameters:

• ByVal: When a parameter is passed by value (ByVal), a copy of the actual parameter value is passed to the function or subroutine. This means that changes made to the parameter within the function or subroutine do not affect the original value outside of the function. ByVal is used when you do not want the original value to be modified.
• ByRef: When a parameter is passed by reference (ByRef), the actual memory address of the parameter is passed to the function or subroutine. This means that changes made to the parameter within the function or subroutine will affect the original value outside of the function. ByRef is used when you want the function to modify the original value.

So, you would use ByVal when you do not want the original value to be modified and use ByRef when you want the function to modify the original value.