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Using a ruby method to return the absolute value of a number

Using a ruby method to return the absolute value of a number

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Alexandre Calaça
·Feb 7, 2020·

2 min read

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Table of contents

  • Intro
  • What's an absolute value?
  • Using the abs method
  • Conclusion

What's up, guys?


Today, I want to share with you how to use a ruby method to return the absolue value of an integer value in Ruby.

What's an absolute value?

I'm not a math geek, but this answer is kinda simple. The absolute value of a number x is its non-negative version, so, it's the number without the negative sign.

For example, the absolute value of the number -4 is 4. The absolute value of the positive 4 is also 4. It doesn't matter the parameter, the absolute value is always the positive version.

Using the abs method


The abs belongs to the numeric class. In Ruby, the numeric class is the highest-level class for numbers.

The abs method returns the absolute value of a given number.

The magnitude method is an alias for the abs method.


The syntax is very simple:


number is the value we want to check the absolute version. . is how we call the method. abs is the method.

Get down to business

Let's check it out:

irb(main):006:0> -9.abs
=> 9

The absolute value of a positive number is the number itself

irb(main):005:0> 9.abs
=> 9

Since The abs method also works with the float type:

rb(main):007:0> -3.4.abs
=> 3.4
irb(main):008:0> 3.4.abs
=> 3.4

A NoMethodError is displayed if it's used with a data type that it doesn't inherit from the numeric class.

irb(main):009:0> "1".abs
Traceback (most recent call last):
        4: from /usr/local/bin/irb:23:in `<main>'
        3: from /usr/local/bin/irb:23:in `load'
        2: from /var/lib/gems/2.5.0/gems/irb-1.1.0/exe/irb:11:in `<top (required)>'
        1: from (irb):9
NoMethodError (undefined method `abs' for "1":String)

Summing up:

  • Syntax: numericvalue.abs()
  • Parameter: numeric value which is to be converted to absolute value.
  • Return: absolute value of the passed numeric value.


In this article, it was possible to learn and practice how to get the absolute value of numbers in Ruby.

Hope it was useful.

That's for today. Let me know if you have any questions.

By the way, you help me a lot if you like and/or share this article.

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