Ruby-Learn

on lession

ruby learn

1. 常见的逻辑处理

1.1 if and case

    var = true
    if var == true then puts "something"
    elsif if var == false then pust "nothing"
    else puts "error"
    end

    case var
      when true:  puts true
      when false: puts false
      else  puts "nothing"
    end


    value = case var
      when true: true
      when false: false
      else "nothing"
    end

1.2 循环（while do/ begin end while ….. break end, upto/downto, until, times）

while i < 10 do
  if i == false then break
  i += 1
end

begin
  i += 1
end while i < 10

until i > 10 do
.......
end

5.times {|i| puts i} / 5.downto(1) {|i| puts i} / 1.upto(5) {|i| puts i}

for i in 1...5(no include 5) / 1..5(include 5) do
.....
end

2. 字符串处理

a = "hello"
b = "world"
a += b
# a << b

puts a[0], a[-1]
a =  "345" * 2   # 345345
a.insert 1, "eeeee"   # a = "3eeeee45"
#others can by doc

a.each_byte/ a.each_char, a.next / a[0].next

3. 数组

3.1 常规使用

arr = []
arr.each/ arr[0]/ arr[-1]/ a[1..4]
arr << "bcd" / arr += "bcd"
a = [] , b = []
a = a | b / a & b | a  - b

3.2 一些数据结构

#栈
stack = []
stack.push "a" #入栈
stack.pop #出栈
#队列
queue = []
queue.push "a" #进队列
queue.shift #出队列
queue.unshift ("a", "b") / queue.unshift #在队列最前面加入数值

4. 哈希

hash = {:name => "something", ....... }
hash = {"name" => "something"}
hash.each |key, value| do
   ......
end

5. 类

class Hello
   def initialize(instance)
     @instance = intance
    end
end

@instance/@@class_instance/$global/Const

class Accessor
  attr: :reader, :writer
  attr_accessor :same
  attr_reader: :only_read
  attr_writer: :only_writer
end
class Area
  def Area.rect
  ....#类方法
  end
end

class parent
private
....
protected
....
end

moudle Dice
  def somefunction
  end
end

require 'file.rb' / 'file'
class Sub < parent
   include Dice
   ......
 end