In Ruby, the **`gusb` method** replaces all occurrences of a pattern with a given replacement and returns the copy of the string. For example, if we want to replace all the vowels in a string with asterisks, the result will be as follows:

# Syntax
The `gsub` method is declared as follows:


# Parameters
The `gsub` method takes two parameters:

* **`pattern`**: This is the substring/character set that will be removed. 

* **`replacement`**: This is the character(s) that will be substituted for the characters to be removed. 

> The `pattern` is typically a #key# `Regexp`: a Regexp holds a regular expression, used to match a pattern against strings #key#. 

# Return value
The `gsub` method returns the copy of the string which contains the `replacement` substituted with the `pattern.`

# Example
The code below shows the use of the `gsub` method in Ruby. The first example returns the copy of the string with its vowels replaced with asterisks. The second example substitutes the pattern with `<>` as a replacement:

# Example 1
puts "Hello".gsub(/[aeiou]/, "*")

# Example 2
puts "Good Morning".gsub(/[ning]/,"<>")

What is the gsub method in Ruby?

In Ruby, gsub replaces all pattern occurrences with a replacement, returning the modified string.