Chapter 3, Problem 4MQ6

Program Plan Intro

Option Strict On:

The Option Strict On statement is used to prevent the data loss in the implicit type conversion.

• If one data type value is converted to a narrower data type, then smaller number or number with fewer precision data loss is occurred in the implicit conversion.
  • For example,
  • Consider the statement Dim intValue As Integer = 18.36
    • Here, the double value is converted as integer number and stored into the memory location.
    • In the implicit conversion, the value is rounded off by the nearest whole number and the decimal portions are removed.
    • At the final result, the number is stored as 18, so the decimal part .36 is removed from the number. Here, the data loss has been occurred.
  • If the Option Strict is On, then it will not allow the implicit conversion; it raises a warning while the program tries to perform an implicit conversion.
• When the Option Strict is on, it does not allow the following conversions:
  • String to number implicit conversion is not allowed.
  • Number to string implicit conversion is not allowed.
  • Wider data types to narrower data types implicit conversion is not allowed.
  • Implicitly narrower data types are promoted as wider data types.