Option Explicit statement and Option Strict Statement

Option Explicit statement and Option Strict Statement

Option Explicit Statement

The Option Explicit has two modes. On and Off mode.

If Option Explicit mode in ON , you have to declare all the variable before you use it in the program . If not , it will generate a compile-time error whenever a variable that has not been declared is encountered .If the Option Explicit mode is OFF , Vb.Net automatically create a variable whenever it sees a variable without proper declaration.
By default the Option Explicit is On

Option Strict Statement
Visual Basic allows conversions of many data types to other data types. Data loss can occur when the value of one data type is converted to a data type with less precision or smaller capacity. A run-time error occurs if such a narrowing conversion fails. Option Strict ensures compile-time notification of these narrowing conversions so they can be avoided.
On
Optional. Enables Option Strict checking.
Off
Optional. Disables Option Strict checking. If On or Off is not specified, the default is Off.