ruby 笔记之七

1.

puts "第八章再说字符串"

str = 'this/'s you string./n'

puts str

str = "this/'s you string./n"

puts str

def hello(name)
  "Welcome ,#{name}!" 
end


puts hello("kaichuan")

puts hello("ruby")

2.

str = "Hello,kaichuan,Welcome!"

=begin
  =~ 这是一个符号
  返回的是一个位置
=end

puts str=~ /kaichuan/

puts str =~ /a/

puts str =~ /ABC/


=begin
  !~ 存在返回false
     不存在返回true
=end

puts str !~ /kaichuan/

puts str !~ /a/

puts str !~ /ABC/


3.

strdoc =<<DOC_EOF
This is windows2000 or windows98 system.
Windows system is BEST?
Windows2000 running in 12-31-2006,……
DOC_EOF



re = /[w|W]indows(?:98|2000)/

strdoc.gsub!(re,"Windows XP")

re = /[1-9][0-9]/-[1-9][0-9]/-/d/d/d/d/
time = Time.now.strftime("%m-%d-%Y") #得到当前时间
strdoc.gsub!(re, time)
puts strdoc

4.

(1..9).each {|i| print i if i<7}

#each 是一个迭代器
print "/n"


def one_block
    yield
   
    yield
   
    yield
  end
 
  one_block {puts "This is a block."}
 
=begin 
begin


  a = "12".to_i
 
  rescue
 
end
=end


def one_block
 
  for num in 1..3
    yield(num)
  end
 
end

one_block do |i|
  puts "This is block#{i}."
end

print "do_something/n"

def do_something
  yield
end

do_something do
    (1..9).each{|i| print i if i<5}
    puts
  end
 
 
  do_something do
    3.times{print "Hi!"}
    puts
  end
 
 
 

5.

class Array
   def one_by_one
      for i in 0...size
        yield(self[i])
      end
      puts
    end
   
  
end


arr = [1,3,5,7,9]

arr.one_by_one {|k| print k,","}

arr.one_by_one{|h|print h*h,","}