Learn Enough Ruby to Be Dangerous: Write Programs, Publish Gems, and Develop Sinatra Web Apps with Ruby

Chapter 4

Other Native Objects

Now that we’ve taken a look at strings and arrays, we’ll continue with a tour of some other important Ruby objects: math, dates, regular expressions, and hashes.

4.1 Math

Like most programming languages, Ruby supports a large number of mathematical operations:

>> 1 + 1
=> 2
>> 2 - 3
=> -1
>> 2 * 3
=> 6
>> 10/5
=> 2

Be especially careful with division, though; it can be counter-intuitive:

>> 10/4
=> 2
>> 2/3
=> 0

Here Ruby uses integer division, which returns the number of times the denominator goes into the numerator. When dividing one number by another, chances are you want floating-point division instead, which you can get by adding a “point zero” to at least one of the numbers:

>> 10/4.0
=> 2.5
>> 2/3.0 ...