N = VAL( A$ )
A$ is a string, LEN >= 1
The value of the numeric-constant associated with A$, if the string associated with A$ is a numeric-constant. Leading and trailing spaces in the string are ignored. If the evaluation of the numeric-constant would result in a value which causes an underflow, then the value returned shall be zero. For example, VAL( “ 123.5 ” ) = 123.5, VAL( “2.E-99” ) could be zero, and VAL( “MCMXVII” ) causes an exception.