Do not use eql? for strings

Metadata

ID: ruby-best-practices/eql-string

Language: Ruby

Severity: Notice

Category: Best Practices

Description

The rule “Do not use eql? for strings” is a standard practice in Ruby programming. The eql? method in Ruby checks if two objects are of the same type and have the same value. While this may seem useful, it can lead to unexpected behavior when comparing strings.

This rule is important because using eql? to compare strings can lead to confusing and hard-to-debug issues. For instance, eql? will return false when comparing a string to a symbol with the same characters, even though they might seem equivalent to a human reader.

To avoid violating this rule, it is recommended to use the == operator when comparing strings. The == operator in Ruby compares the values of two objects for equality, and is more intuitive for string comparisons. For example, instead of writing 'ruby'.eql? some_str, you should write 'ruby' == some_str. This will help to avoid potential confusion and make your code more readable and maintainable.

Non-Compliant Code Examples

'ruby'.eql? some_str

Compliant Code Examples

'ruby' == some_str
1.0.eql?