Question

Im trying to read a column of String values from my DB. Im trying to convert them to floats. I have written the following method to do that

def initialize (db_listings)
    db_listings.each do |listing| 
        name = listing.name 
        index = listing.id
        lat_string = listing.latitude
        long_string = listing.longitude
        puts "name = #{name}"
        puts "index = #{index}"
        puts "Converting #{lat_string} to float"
        puts "Converting #{long_string} to float"
        if(lat_string == nil || long_string == nil )
            lat_float = Float(9999)
            long_float = Float(9999)
        else
            lat_float = Float(lat_string)
            long_float = Float(long_string)
        end   

        puts "Now printing floats"

        puts lat_float
        puts long_float

    end



end

But I get the following error:

Throwing an error:ArgumentError: invalid value for Float(): ""

This is because it encountered an empty entry for that column.

My question is : WHy did the if else statement in my method not catch it?

How do I adjust my method for empty/invalid values in the database?

Thanks

Answer 1

From the error message I presume lat_string and long_string are empty strings rather than nil. You could use blank? to catch both nil and empty strings:

    if(lat_string.blank? || long_string.blank?)
        lat_float = Float(9999)
        long_float = Float(9999)
    else
        lat_float = Float(lat_string)
        long_float = Float(long_string)
    end