详细解析Ruby中的变量

#!/usr/bin/ruby

$global_variable = 10
class Class1
 def print_global
   puts "Global variable in Class1 is #$global_variable"
 end
end
class Class2
 def print_global
   puts "Global variable in Class2 is #$global_variable"
 end
end

class1obj = Class1.new
class1obj.print_global
class2obj = Class2.new
class2obj.print_global

#!/usr/bin/ruby

class Customer
  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 address #@cust_addr"
  end
end

# Create Objects
cust1=Customer.new("1", "John", "Wisdom Apartments, Ludhiya")
cust2=Customer.new("2", "Poul", "New Empire road, Khandala")

# Call Methods
cust1.display_details()
cust2.display_details()

Customer id 1
Customer name John
Customer address Wisdom Apartments, Ludhiya
Customer id 2
Customer name Poul
Customer address New Empire road, Khandala

#!/usr/bin/ruby

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 address #@cust_addr"
  end
  def total_no_of_customers()
    @@no_of_customers += 1
    puts "Total number of customers: #@@no_of_customers"
  end
end

# Create Objects
cust1=Customer.new("1", "John", "Wisdom Apartments, Ludhiya")
cust2=Customer.new("2", "Poul", "New Empire road, Khandala")

# Call Methods
cust1.total_no_of_customers()
cust2.total_no_of_customers()

Total number of customers: 1
Total number of customers: 2

#!/usr/bin/ruby

class Example
  VAR1 = 100
  VAR2 = 200
  def show
    puts "Value of first Constant is #{VAR1}"
    puts "Value of second Constant is #{VAR2}"
  end
end

# Create Objects
object=Example.new()
object.show

Value of first Constant is 100
Value of second Constant is 200

123         # Fixnum decimal
1_234        # Fixnum decimal with underline
-500         # Negative Fixnum
0377         # octal
0xff         # hexadecimal
0b1011        # binary
"htmlcode">

123.4        # floating point value
1.0e6        # scientific notation
4E20         # dot not required
4e+20        # sign before exponential




字串常值：
Ruby字符串是简单的8位字节序列，它们是String类的对象。双引号字符串可以替代和反斜线符号，但不允许单引号替换和只允许反斜线符号 \\ 和 \'
例如：


#!/usr/bin/ruby -w

puts 'escape using "\\"';
puts 'That\'s right';




这将产生以下结果：


escape using "\"
That's right




也可以替换成一个字符串使用＃{expr}序列表示任何Ruby表达式的值。表达式expr 可以是任何Ruby的表达式。


#!/usr/bin/ruby -w

puts "Multiplication Value : #{24*60*60}";




这将产生以下结果：


Multiplication Value : 86400




反斜线符号说明：
以下是Ruby支持的反斜线符号列表：



 Ruby字符串的更多详细信息，请通过 Ruby字符串.

Ruby数组:
Ruby的数组是由放置对象引用方括号之间用逗号分隔的一系列字面。逗号结尾被忽略。

例如：


#!/usr/bin/ruby

ary = [ "fred", 10, 3.14, "This is a string", "last element", ]
ary.each do |i|
  puts i
end




这将产生以下结果：


fred
10
3.14
This is a string
last element




Ruby的数组的更多细节，经过 Ruby数组.

Ruby 哈希:
字面上Ruby创建哈希放置括号之间的键/值对列表，以逗号或序列=>之间的键和值。逗号结尾被忽略。

例如：


#!/usr/bin/ruby

hsh = colors = { "red" => 0xf00, "green" => 0x0f0, "blue" => 0x00f }
hsh.each do |key, value|
  print key, " is ", value, "\n"
end




这将产生以下结果：


green is 240
red is 3840
blue is 15




对于更详细的Ruby哈希，经过 Ruby哈希.

Ruby的范围：
范围代表的间隔。一组的开始和结束的值。可能被使用s..e 和s...e文字，或具有Range.new范围。
范围使用..包含运行从开始到结束。创建使用...排除最终值。当作为一个迭代器，范围序列中的每个值将返回。
range (1..5) 表示，它包括1，2，3，4，5值，range (1...5) 表示，它包括1，2，3，4这四个值。

实例:


#!/usr/bin/ruby

(10..15).each do |n| 
  print n, ' ' 
end




这将产生以下结果：


10 11 12 13 14 15