ruby学习--varaible

#全局变量
$global_variable=10
class Class1
    def print_global()
        puts "Global variable in Class1 is #{$global_variable}"
    end
end
class1obj=Class1.new
class1obj.print_global()

#实例变量
class Customer
    def initialize(id,name,addr)
        @cust_id=id
        @cust_name=name 
        @cust_addr=addr
    end
    def display_detalis
        puts "Customer id #{@cust_id}"
        puts "Customer name #{@cust_name}"
        puts "Customer addr #{@cust_addr}"
    end
end
cust1=Customer.new("1","John","Wisdom")
cust1.display_detalis

#类变量
class Customer
    @@no_of_customers=0
    def initialize(id,name,addr)
        @cust_id=id
        @cust_name=name
        @cust_addr=addr
    end
    def display_details()
        puts "Customer id #{@cust_id}"
        puts "Customer name #{@cust_name}"
        puts "Customer addr #{@cust_addr}"
    end
    def total_no_of_customers()
        @@no_of_customers +=1
        puts "Totla number of customers:#{@@no_of_customers}"
    end
end
cust1=Customer.new("1","John","Wisdom")
cust2=Customer.new("2","Poul","New")

cust1.total_no_of_customers
cust2.total_no_of_customers