Ruby in a Nutshell

Name

Assignment

Synopsis

target = expr

The following elements may assign targets:

Global variables

Assignment to global variables alters global status. It isn’t recommended to use (or abuse) global variables. They make programs cryptic.

Local variables

Assignment to uninitialized local variables also serves as variable declaration. The variables start to exist until the end of the current scope is reached. The lifetime of local variables is determined when Ruby parses the program.

Constants

Assignment to constants may not appear within a method body. In Ruby, re-assignment to constants isn’t prohibited, but it does raise a warning.

Attributes

Attributes take the following form:

expr.attr

Assignment to attributes calls the attr= method of the result of expr.

Elements

Elements take the following form:

expr[arg...]

Assignment to elements calls the []= method of the result of expr.