Ruby范例1

1.JAVA里的输出函数是:System.out.println("Hello world"); Ruby的输出函数为:puts "HelloWorld"

2.全局变量定义用$符号定义;实例变量用@符号定义

3.如果有多个变量,用下划线隔开

4.在Ruby中主要的集合类是:数组和哈希表,数组的键值是Integer类型的,而哈希表中支持任意类型

例子:

a = [ 1, 'cat', 3.14 ] # 定义数组
输入:a[0] 

输出: 1

输入:a[2] = nil
# 输出a数组所有的元素

输入:a

输出:[1, "cat", nil]

数组另外一种定义方式:

a = %w{ ant bee cat dog elk }

2.变量例子

Local:name,fish_and_chips,x_axis,thx1138,_26

Global:$DEBUG,$CUSTOMER,$_,$PLAN9,$GLOBAL

Instance:@name,@point_1,@x,@_,@plan9

Class:@@total,@@symtab,@@N,@@x_pos,@@SINGLE

Constants and Class Names:PI,String,MyClass,JazzSong

3.定义Hash

写法1：

music={"1"=>"zhoujielun","2"=>"caiyilin"}

输入:music["1"]

输出:zhoujielun

写法2:

histogram = Hash.new(0)
histogram['key1'] ! 0
histogram['key1'] = histogram['key1'] + 1
histogram['key1'] ! 1