Difference between And("&") and AndAlso("&&") Operator

And(“&”) Operator:

  Ø  It evaluates both sides even first condition goes wrong.

  Ø  It takes longer to execute for long expression.

  Ø  Example:

‘It throws exception.

If dt IsNot Nothing And dt.Rows.Count > 0

        ‘Bind Gridview Logic

End If

AndAlso(“&&”) Operator:

  Ø  It only evaluates the right side if the left side is true.

  Ø  Its faster compare to And operator.

  Ø  Example:

‘Works fine without exception.

If dt IsNot Nothing AndAlso dt.Rows.Count > 0

        ‘Bind Gridview Logic.

Else

        ‘No data found.

End If

Note: Same logic can apply for Or(“|”) and OrElse(“||”)