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    Ruby语法笔记

    作者:admin 时间:2021-02-03 06:15

    接受用户输入

    first_name = gets.chomp
    

    首字母大写

    first_name.capitalize!
    

    字母变大写

    first_name.upcase!
    

    字母变小写

    first_name.downcase!
    

    多行输出

    print <<EOF
      # 多行输出
    EOF
    

    注释

    # 我是注释
    

    变量获取

    #{first_name}
    

    变量

    1. 全局变量 $
    2. 类变量 @@
    3. 方法变量 @
    4. 局部变量 小写字母或_

    if/else

    if a < b
      puts '1'
    elsif b < a
      puts '2'
    end    
    


    class Classname
      def functionname(params)
        puts params
      end
    end
    
    class1 = Classname.new
    class1.functionname('1')
    unless
    unless false
      print 'ok'
    else
      print 'no'
    end    
    
    

    是否包含字符

    print 'puts'
    
    user_input = gets.chomp
    
    user_input.downcase!
    
    if user_input.include?"s"
      print 'has s'
    end
    
    

    替换字符

    # s -> th
    user_input.gsub!(/s/,"th")
    

    在字符串中输出变量值

    puts 'okok #{user_input}'
    

    while

    counter = 1
    
    while counter < 11
      puts counter
      counter = counter + 1
    end
    

    Until

    counter = 1
    until counter > 10
      print counter
      counter = counter + 1
    end 
     
    

    += 、 -= 、 *=、 /=
    Some languages have the increment operators ++ and -- (which also add or subtract 1 from a value), but Ruby does not
    for循环
    # 如果 1...10 包含1-9,如果 1..10 包含1-10

    for num in 1...10
      puts num
    end  
    

    Loop Method
    An iterator is just a Ruby method that repeatedly invokes a block of code.

    i = 20
    loop do
      i -= 1
      print "#{ i }"
      break if i <= 0
    end  
    

    Next

    i = 20
    loop do
     i -= 1
     next if i%2 != 0
     print "#{i}"
     break if i <= 0
    end
    

    数组

    my_array = [1,2,3,4,5]
    

    The .each Iterator迭代器

    numbers = [1, 2, 3, 4, 5]
    
    # one way to loop
    numbers.each { |item| puts item }
    
    # another way to loop
    numbers.each do |item|
     puts item
    end
    
    

    The .times Iterator 次数迭代器

    10.times { print 'ok'})
    

    Looping with 'While'

    num = 1
    
    while num <= 50 do
      print num
      num += 1
    end  
    
    

    Looping with 'Until'

    num = 1
    until num > 50 do
      print num
      num += 1
    end  
    

    Loop the Loop with Loop

    num = 0
    
    loop do
      num += 1
      print "Ruby!"
      break if num == 30
    end  
    
    

    The .split Method,

    text.split(",")
    
    puts "Text to search through: "
    text = gets.chomp
    puts "Word to redact"
    redact = gets.chomp
    
    words = text.split(" ")
    
    words.each do |word|
      print word
    end
    

    js
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