Ruby Number Methods


title: Ruby Number Methods

Ruby provides a variety of built-in methods you may use on numbers. The following is an incomplete list of integer and float methods.

Even:

Use .even? to check whether or not an integer is even. Returns a true or false boolean.

15.even? #=> false 4.even? #=> true

Odd:

Use .odd? to check whether or not an integer is odd. Returns a true or false boolean.

15.odd? #=> true 4.odd? #=> false

Ceil:

The .ceil method rounds floats up to the nearest number. Returns an integer.

8.3.ceil #=> 9 6.7.ceil #=> 7

Floor:

The .floor method rounds floats down to the nearest number. Returns an integer.

8.3.floor #=> 8 6.7.floor #=> 6

Next:

Use .next to return the next consecutive integer.

15.next #=> 16 2.next #=> 3 -4.next #=> -3

Pred:

Use .pred to return the previous consecutive integer.

15.pred #=> 14 2.pred #=> 1 (-4).pred #=> -5

To String:

Using .to_s on a number (integer, floats, etc.) returns a string of that number.

15.to_s #=> "15" 3.4.to_s #=> "3.4"

To Float:

Converts an Integer to a Float.

15.to_f #=> 15.0

Absolute value:

Returns the absolute value of the integer.

-12345.abs #=> 12345 12345.abs #=> 12345

Greatest Common Denominator:

The .gcd method provides the greatest common divisor (always positive) of two numbers. Returns an integer.

15.gcd(5) #=> 5 3.gcd(-7) #=> 1

Round:

Use .round to return a rounded integer or float.

1.round #=> 1 1.round(2) #=> 1.0 15.round(-1) #=> 20

Times:

Use .times to iterate the given block int times.

5.times do |i| print i, " " end #=> 0 1 2 3 4

This article needs improvement. You can help improve this article. You can also write similar articles and help the community.