## Example 1

a = 4
b = 2

2.times do |a|
a = 5
puts a
end

puts a
puts b

The code outputs 5 two times and returns nil, then outputs 4 and returns nil, then outputs 2 and returns nil.

On line 1 we are initializing local variable a to Integer object 4.

On line 2 we are initializing local variable b to Integer object 2.

On line 4-7 we are calling method times on Integer object 2 and passing in a do..end as an argument to it. Afterwards, method times returns the Integer object it was called upon.

The do..end block is executed two times, passing in a as a parameter.

On line 5 we are reassigning the local variable a to Integer object 5.

On line 9 we are calling the method puts and passing in the local variable a as an argument to it.

On line 10 we are calling the method puts and passing in the local variable b as an argument to it.

This code demonstrates the concept of variable shadowing.

Time: 08:28

## Example 2

n = 10

1.times do |n|
n = 11
end

puts n

The code outputs 10 and returns nil.

On line 1 we are initializing local variable n to an Integer object of value 10.

On line 3-5 we are calling the method times on Integer object 1 and passing in the do..end block as an argument. The do..end block is executed as many times as the integer method times is called upon, passing in local variable n as an argument to it.

On line 4 we are reassigning the local variable n to Integer object 11.

On line 7 we are calling the method puts, passing in the local variable n. This method outputs the value n points to (10) and returns nil.

This code demonstrates the concept of variable shadowing. As the variable outside the block and inside have the same name, the variable outside the block cannot be accessed from inside the block.

Time: 06:10

## Example 3

animal = "dog"

loop do |animal|
animal = "cat"
break
end

puts animal

The code outputs "dog" and returns nil.

On line 1 we are initializing local variable animal to a String object of value "dog".

On line 3-6 we are calling the loop method and passing in a do..end block to it as a parameter. The do..end block is executed until the break condition is met, passing in the parameter animal to it.

On line 4 we are reassigning the local variable animal to "cat".

On line 5 we are breaking out of the loop with the break keyword.

On line 8 we are calling the method puts passing in local variable animal to it.

This code demonstrates the concept of variable shadowing. Here, the local variable animal has the same name as the local variable animal passed in as a paramter of do..end block, therefore the latter cannot access the variable of the outer scope.

Time: 06:45