Ruby’s 4 Shades of Equality – Learn to Compare Like a Pro

Ever wondered why ==, ===, eql?, and equal? all exist in Ruby? They look similar but behave very differently — and using the wrong one could cause subtle bugs.

🔸 == Value Equality

Compares what’s inside. If values look the same, it returns true.

5 == 5         # true
[1, 2] == [1, 2]  # true

Use when comparing data, strings, numbers, arrays, etc.

🔸 === Case Equality

Used in case statements. Matches based on type or pattern.

String === "Hello"  # true
(1..10) === 5       # true

Use when writing clean, readable case blocks.

🔸 eql? Value + Type Equality

Stricter than ==. Checks both value and data type.

5 == 5.0        # true
5.eql?(5.0)     # false

Use inside Hashes for precise key matching.

🔸 equal? Object Identity

Checks if two variables point to the same object in memory.

a = "hello"
b = "hello"
a.equal?(b)    # false

c = a
a.equal?(c)    # true

Use when identity matters (rarely needed in daily Rails code).

⚡ TL;DR