ruby frozen_string_literal

Explanation of Ruby's frozen_string_literal

The frozen_string_literal pragma in Ruby allows you to specify whether all string literals in the file should be frozen by default. When a string is frozen, it cannot be modified. This can help prevent accidental modification of strings and improve performance in certain cases.

1. Enabling frozen_string_literal

To enable the frozen_string_literal pragma, you can add the following comment at the beginning of your Ruby file: ruby # frozen_string_literal: true

1. Effects of Enabling frozen_string_literal

Once the frozen_string_literal pragma is enabled, all string literals in the file will be frozen by default. This means that you cannot modify these strings after they have been defined. For example: ruby str = "hello" str << " world" # This will raise a RuntimeError because the string is frozen

1. Performance Benefits

By freezing string literals, Ruby can optimize memory usage and improve performance in some scenarios. Additionally, it can help catch accidental string mutations that might lead to unexpected behavior in your program.

1. Disabling frozen_string_literal

If you want to disable the frozen_string_literal pragma for a specific section of code, you can use the following comment: ruby # frozen_string_literal: false

This will revert the behavior to the default, where string literals are not automatically frozen.

By understanding and using the frozen_string_literal pragma, you can control the default freezing behavior of string literals in your Ruby code, leading to more predictable and efficient string handling.