- Inheritance
The Comparable mixin is used by classes whose objects may be ordered. The class must define the <=> operator, which compares the receiver against another object, returning -1, 0, or +1 depending on whether the receiver is less than, equal to, or greater than the other object. Comparable uses <=> to implement the conventional comparison operators (<, <=, ==, >=, and >) and the method between?.
class SizeMatters
include Comparable
attr :str
def <=>(anOther)
str.size <=> anOther.str.size
end
def initialize(str)
@str = str
end
def inspect
@str
end
end
s1 = SizeMatters.new("Z")
s2 = SizeMatters.new("YY")
s3 = SizeMatters.new("XXX")
s4 = SizeMatters.new("WWWW")
s5 = SizeMatters.new("VVVVV")
s1 < s2 #=> true
s4.between?(s1, s3) #=> false
s4.between?(s3, s5) #=> true
[ s3, s2, s5, s4, s1 ].sort #=> [Z, YY, XXX, WWWW, VVVVV]
Methods
Instance
| Visibility | Signature |
|---|---|
| public | < (p1) |
| public | <= (p1) |
| public | == (p1) |
| public | > (p1) |
| public | >= (p1) |
| public | between? (p1, p2) |
Instance Method Detail
obj < other => true or false
Compares two objects based on the receiver‘s <=> method, returning true if it returns -1.
obj <= other => true or false
Compares two objects based on the receiver‘s <=> method, returning true if it returns -1 or 0.
obj == other => true or false
Compares two objects based on the receiver‘s <=> method, returning true if it returns 0. Also returns true if obj and other are the same object.
obj > other => true or false
Compares two objects based on the receiver‘s <=> method, returning true if it returns 1.
obj >= other => true or false
Compares two objects based on the receiver‘s <=> method, returning true if it returns 0 or 1.
obj.between?(min, max) => true or false
Returns false if obj <=> min is less than zero or if anObject <=> max is greater than zero, true otherwise.
3.between?(1, 5) #=> true
6.between?(1, 5) #=> false
'cat'.between?('ant', 'dog') #=> true
'gnu'.between?('ant', 'dog') #=> false