break can return a value

Explanation

Explanation of the Code

(1..10).each { |n| break n if n == 5 } # => 5

1. Range Creation: (1..10)

   • This creates a Range object representing the sequence of numbers from 1 to 10, inclusive.

2. Iteration: .each { |n| ... }

   • The each method is called on the Range object. each iterates over each element in the range, passing each element to the block as n.

3. Block Execution: { |n| break n if n == 5 }

   • For each element n in the range, the block executes the code inside it. The block checks if n is equal to 5. If the condition is met (n == 5), the break keyword is executed with the argument n.

The break Keyword

• Definition: break is used to exit a loop or iterator early.
• Interaction with Scope: When break is called, it immediately terminates the loop or iteration and returns the value provided to break as the result of the entire loop or iterator.
• Default Behavior: If no argument is provided to break, it returns nil.

Detailed Breakdown of the Code

• The each method starts iterating over the range (1..10).
• For each number n, the block checks if n is equal to 5.
• When n is 1, 2, 3, or 4, the condition n == 5 is false, so the loop continues to the next iteration.
• When n is 5, the condition n == 5 is true, so break n is executed.
• The break n statement exits the loop and returns the value of n (which is 5) as the result of the entire each method.
• Thus, the code (1..10).each { |n| break n if n == 5 } returns 5.

Example with Default Return Value of break

If break is used without an argument, it returns nil by default:

result = (1..10).each { |n| break if n == 5 }
puts result # => nil

• Here, when n is 5, break is called without an argument.
• This causes the loop to exit and return nil as the result of the each method.

Example with Custom Return Value

You can provide a custom argument to break to return a specific value:

result = (1..10).each { |n| break 42 if n == 5 }
puts result # => 42

• In this example, when n is 5, break 42 is executed.
• This causes the loop to exit and return 42 as the result of the each method.

Summary

• The break keyword is used to exit a loop or iterator early.
• By default, break returns nil if no argument is provided.
• You can provide an argument to break to return a specific value.
• In the example (1..10).each { |n| break n if n == 5 }, the loop exits when n is 5, returning 5 as the result.