Ruby | Set add? function

The add? is an inbuilt method in Ruby which adds the given object to the set and returns self. If the object is already in the set, returns nil.

Syntax: s1.name.add?(object)

Parameters: The function takes the object to be added to the set.

Return Value: It returns self if the object is not in the set and is added, it returns nil if it is already in the set.

Example 1:

#Ruby program to illustrate the add ? method

#requires the set
require "set"

    s1
    = Set[2, 1]

#Enters 4 into it
      puts s1.add
    ? (4)

#Enters 4 into it
#But set has already 4
          puts s1.add
    ? (4)

Output:

Set: {2, 1, 4}

Example 2:

#Ruby program to illustrate the add ? method

#requires the set
require "set"

    s1
    = Set[5]

#Enters 5 into it
#But set has already 5
      puts s1.add
    ? (5)

#Enters 8 into it
          puts s1.add
    ? (8)

Output:

Set: {5, 8}

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