Block & outer vars

Explanation

a = "outer"
1.times do
  a = "inner"
end

a # => "inner"

Variable Initialization

The variable a is initialized outside of the block with the value "outer".

a = "outer"

Block Execution

The block 1.times do ... end is executed once (since .times iterates the specified number of times—in this case, once).

Inside the block, the variable a is assigned a new value "inner".

1.times do
  a = "inner"
end

What Happens to a Inside the Block?

In Ruby, local variables inside blocks can access and modify variables from the outer scope. The a inside the block is not a new variable—it refers to the same a that was defined before the block.

Therefore, the assignment a = "inner" modifies the outer a.

Final Value of a

After the block completes, the variable a retains its new value "inner" because the modification inside the block is reflected in the outer scope.

a # => "inner"

Key Takeaways:

• Ruby's block scoping: Ruby allows blocks to access and modify local variables from their enclosing scope. This is different from some other languages where blocks introduce a new scope for variables.
• Variable mutation within a block: If you modify a variable inside a block, the modification is reflected outside of the block as well.