Ruby: how can I copy a variable without pointing to the same object?

In Ruby, how can I copy a variable such that changes to the original don't affect the copy?

For example:

phrase1 = "Hello Jim"
phrase2 = phrase1
phrase1.gsub!("Hello","Hi")
p phrase2 #outputs "Hi Jim" - I want it to remain "Hello Jim"

In this example, the two variables point to the same object; I want to create a new object for the second variable but have it contain the same information initially.

As for copying you can do:

phrase2 = phrase1.dup

or

# Clone: copies singleton methods as well
phrase2 = phrase1.clone

You can do this as well to avoid copying at all:

phrase2 = phrase1.gsub("Hello","Hi")

Using your example, instead of:

phrase2 = phrase1

Try:

phrase2 = phrase1.dup

phrase1 = "Hello Jim"
   # => "Hello Jim"

phrase2 = Marshal.load(Marshal.dump(phrase1))
   # => "Hello Jim"

phrase1.gsub!("Hello","Hi")
   #  => "Hi Jim" 

puts phrase2
   # "Hello Jim"

puts phrase1
   # "Hi Jim"