Example

> strtod("1.23")
     1.23  
> a = strtod("1.23")
 a =
     1.23  
> class(a)
num
> b = strtod("2.12345e45")
 b =
 2.12e+45  
> class(b)
num
> c = strtod("3+4j")
 c =
        3  
> d = strtod("hello")
 d =
        0