What's the difference between a string and a symbol in Ruby?

Question

What\'s the difference between a string and a symbol in Ruby and when should I use one over the other?

Answer 1

There are two main differences between String and Symbol in Ruby.

1. String is mutable and Symbol is not:

   • Because the String is mutable, it can be change in somewhere and can lead to the result is not correct.
   • Symbol is immutable.

2. String is an Object so it needs memory allocation

   puts "abc".object_id # 70322858612020
   puts "abc".object_id # 70322846847380
   puts "abc".object_id # 70322846815460
   

   In the other hand, Symbol will return the same object:

   puts :abc.object_id # 1147868
   puts :abc.object_id # 1147868
   puts :abc.object_id # 1147868
   

So the String will take more time to use and to compare than Symbol.

Read "The Difference Between Ruby Symbols and Strings" for more information.