Code Blocks in Verse

A code block, or block, is a group of zero or more expressions that introduces a new scoped body. (A block with zero expressions would be an empty block, and ideally would only be used as a placeholder to be filled in later.)

Code blocks can only appear after identifiers.

Scope refers to the part of the program where the association of an identifier (name) to a value is valid, and where that name can be used to refer to the value. For example, any constants or variables that you create within a code block only exist in the context of the code block. This means that the lifetime of objects is limited to the scope they're created in and they cannot be used outside of that code block.

The following example shows how to calculate the maximum number of arrows that can be bought with the number of coins the player has. The constant MaxArrowsYouCanBuy is created within the if block and therefore its scope is limited to the if block. When the constant MaxArrowsYouCanBuy is used in the print string, it produces an error because the name MaxArrowsYouCanBuy doesn't exist in the scope outside of the if expression.