Ruby中的逻辑运算以及符号做为方法名

#第十二课 逻辑运算
a,b = true, false
puts a && b #逻辑与运算
puts a || b #逻辑或运算
puts !a #取反
puts !b
puts c = (4 >3)
puts (4 > 3) && b

#三元运算
a, b = 4,5
puts c = (a > b) ? a : b

#范围运算
(2..5).each do |n|#从2到5闭区间
print n
end

(2...5).each do |n|#从2到4左闭右开
print n
end

#Ruby中符号也可以是方法名
class Student
Version = 2#常量
@@all_num = 2 #全局变量得要初始化不然要报错
include Math #导入Mathm模块 Mix-in
extend Math
def initialize(name, num, sex)
@name = name
@num = num
@sex = sex
end

class << self
def class_fun
puts "这是一个类方法"
end

def class_fun2
puts "这也是一个类方法"
end
end

def self.class_fun3
puts "这是类方法的另外一种写法"
end
#相当于Java中的get方法
def get_name
@name
puts @@all_num += 1
end

def name
@name
end
#相当于Java中的set方法
def name=(value)
@name = value
end

def set_name(name)
@name = name
puts @@all_num += 1
end
end

class Student
def expend
puts "扩展类"
end
end

class MiddleStudent < Student
attr_reader :name
attr_writer :name
def initialize(name)
@name = name
end

def sub_fun
puts "这是子类的方法#{@name}"
end
end

puts s = Student.new("young", 20, "男")
puts s.get_name
puts s.name
puts s.set_name("改了个名字")
puts s.name =("改了个好名字")
m = MiddleStudent.new("初中生")
puts m.name

class Vector
attr_accessor :x, :y
def initialize(x, y)
@x = x
@y = y
end

def +(value) #符号+做为方法名
Vector.new(@x + value.x, @y + value.y)
end

def -(value)#符号-做为方法名
Vector.new(@x - value.x, @y - value.y)
end
end

p a = Vector.new(3, 5)
p b = Vector.new(6, 9)

p a + b
p a - b