Ruby | Set < method

The < is an inbuilt method in Ruby that returns true if a set if a proper subset of another set. If it is not a proper subset, then it returns false.

Syntax: s1.name < s2.name

Parameters: The function does not takes any parameter.

Return Value: It returns true if set s1 is a proper subset of s2, else it returns false.

Example 1:

#Ruby program to illustrate the < method

#requires the set
require "set"

    s1
    = Set[1, 2] s2 = Set[1, 2, 3]

# <method used
                     puts s1
                     < s2

Output:

true

Example 2:

#Ruby program to illustrate the < method

#requires the set
require "set"

    s1
    = Set[1, 5] s2 = Set[1, 2, 3]

# <method used
                     puts s1
                     < s2

Output:

false

Reference: https://devdocs.io/ruby~2.5/set#method-i-3C