Programming Ruby 3.3

Names

Ruby names are used to refer to constants, variables, methods, classes, and modules. The first character of a name helps Ruby determine its intended use. Certain names, listed in the following table, are keywords and shouldn’t be used as variable, method, class, or module names. (Technically, many of these names are legal method or variable names; it’s just very confusing to use them in that way.) Method names are described later in ​Method Definition​.

Table 18. Reserved words

__ENCODING__		__FILE__	__LINE__	BEGIN	END	alias	and	begin
break	case	class	def	defined?	do	else	elsif	end
ensure	false	for	if	in	module	next	nil	not
or	redo	rescue	retry	return	self	super	then	true
undef	unless	until	when	while	yield

In these descriptions, an uppercase letter is a capital letter from any ...