Ruby语法笔记

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接受用户输入

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first_name = gets.chomp

首字母大写

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first_name.capitalize!

字母变大写

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first_name.upcase!

字母变小写

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first_name.downcase!

多行输出

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print <<EOF
  # 多行输出
EOF

注释

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# 我是注释

变量获取

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#{first_name}

变量

全局变量 $
类变量 @@
方法变量 @
局部变量小写字母或_

if/else

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

类

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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

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print 'puts'

user_input = gets.chomp

user_input.downcase!

if user_input.include?"s"
  print 'has s'
end

替换字符

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

在字符串中输出变量值

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puts 'okok #{user_input}'

while

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counter = 1

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

Until

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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

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for num in 1...10
  puts num
end

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

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

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

数组

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

The .each Iterator迭代器

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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

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10.times { print 'ok'})

Looping with 'While'

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num = 1

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

Looping with 'Until'

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

Loop the Loop with Loop

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num = 0

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

The .split Method,

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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