Updated: August 2009
Returns an expression that has been converted to a Variant of subtype Long.
The expression argument is any valid expression.
Use the CLng function to provide conversions from any data type to a Long subtype. For example, CLng forces integer arithmetic when currency, single-precision, or double-precision arithmetic would normally occur.
The CLng function uses the locale setting of your system to determine how to perform conversions. Different decimal separators are properly recognized depending on the locale setting, as are different thousand separators.
If expression lies outside the acceptable range for the Long subtype, an error occurs.
The following example uses the CLng function to convert a value to a Long:
Dim MyVal1, MyVal2, MyLong1, MyLong2 MyVal1 = 25427.45: MyVal2 = 25427.55 ' MyVal1, MyVal2 are Doubles. MyLong1 = CLng(MyVal1) ' MyLong1 contains 25427. MyLong2 = CLng(MyVal2) ' MyLong2 contains 25428.
When the fractional part of a value is exactly 0.5, the CLng function rounds to the closest even number. For example, 0.5 rounds to 0, 1.5 rounds to 2, and 3.5 rounds to 4. The purpose of rounding to the closest even number is to compensate for a bias that could accumulate when many numbers are added together.
CLng differs from the Fix and Int functions, which truncate, rather than round, the fractional part of a number.