All replacements in Ruby are done using String#gsub. This method does both
regular expression and string based replacements.
{{code:php $result = str_replace('Hello', 'Hi', 'Hello world'); var_export($result); // => 'Hi world' }}
{{code:ruby p "Hello world".gsub("Hello", "Hi") # => "Hi world" }}
Ruby also has the String#gsub! method which modifies the string value
directly.
{{code:ruby my_string = "Hello world"
# the original string remains the same (we use the return value)
my_string.gsub("Hello", "Hi")
p my_string
# => "Hello world"
# the original string is modified
my_string.gsub!("Hello", "Hi")
p my_string
# => "Hi world"
}}
{{related: strings/str_ireplace strings/substr_replace pcre/preg_replace strings/strtr }}