Ruby | Queue shift() function

The shift() is an inbuilt function in Ruby returns the element in the front of the queue and removes it from the queue.

Syntax: q_name.shift()

Parameters: The function does not takes any element.

Return Value: It returns the first element which is at the front of the queue and removes it from the queue.

Example 1:

#Ruby program for shift() function in Queue

#Create a new QUEUE q1
q1 = Queue.new

#push 5
     q1.push(5)

#push 6
         q1.push(6)

#Prints the top - most element and also shifts it
             puts q1.shift

                 puts q1.shift

Output:

5
6

Example 2:

#Ruby program for shift function in Queue

#Create a new QUEUE q1
q1 = Queue.new

#push 12
     q1.push(12)

#push 21
         q1.push(21)

#Prints the top - most element and also shifts it
             puts q1.shift

                 puts q1.shift

Output:

12
21

Reference: https://devdocs.io/ruby~2.5/queue#method-i-shift