til/ruby/split-a-float-into-its-integer-and-decimal.md

Split A Float Into Its Integer And Decimal

Let's say we have a float value like 3.725. We want to break it up into its constituent parts -- the integer part (3) and the decimal part (0.725).

This can be done with the divmod method on the Numeric class.

3.725.divmod(1)
=> [3, 0.7250000000000001]

In the general case, this method gives you the quotient and the modulus of dividing the number by the given value. When that given value is specifically 1, it will give you those two parts of the float.

One place where this might be useful is when trying to convert a float representing an amount of time into hours and minutes.

hours = 3.725

hours_digit, percentage_minutes = hours.divmod(1)

minutes = (60 * percentage_minutes).to_i
hours_standard = "#{hours_digit}:#{minutes}"

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